/*
  -------------------------------------------------------------------------
		      JavaScript Form Validator (gen_validatorv31.js)
              Version 3.1.2
	Copyright (C) 2003-2008 JavaScript-Coder.com. All rights reserved.
	You can freely use this script in your Web pages.
	You may adapt this script for your own needs, provided these opening credit
    lines are kept intact.
		
	The Form validation script is distributed free from JavaScript-Coder.com
	For updates, please visit:
	http://www.javascript-coder.com/html-form/javascript-form-validation.phtml
	
	Questions & comments please send to form.val at javascript-coder.com
  -------------------------------------------------------------------------  
*/
function Validator(frmname)
{
  this.formobj=document.forms[frmname];
	if(!this.formobj)
	{
	  alert("Error: couldnot get Form object "+frmname);
		return;
	}
	if(this.formobj.onsubmit)
	{
	 this.formobj.old_onsubmit = this.formobj.onsubmit;
	 this.formobj.onsubmit=null;
	}
	else
	{
	 this.formobj.old_onsubmit = null;
	}
	this.formobj._sfm_form_name=frmname;
	this.formobj.onsubmit=form_submit_handler;
	this.addValidation = add_validation;
	this.setAddnlValidationFunction=set_addnl_vfunction;
	this.clearAllValidations = clear_all_validations;
    this.disable_validations = false;//new
    document.error_disp_handler = new sfm_ErrorDisplayHandler();
    this.EnableOnPageErrorDisplay=validator_enable_OPED;
	this.EnableOnPageErrorDisplaySingleBox=validator_enable_OPED_SB;
    this.show_errors_together=true;
    this.EnableMsgsTogether=sfm_enable_show_msgs_together;
    document.set_focus_onerror=true;
    this.EnableFocusOnError=sfm_validator_enable_focus;

}

function sfm_validator_enable_focus(enable)
{
    document.set_focus_onerror = enable;
}

function set_addnl_vfunction(functionname)
{
  this.formobj.addnlvalidation = functionname;
}

function sfm_set_focus(objInput)
{
    if(document.set_focus_onerror)
    {
        objInput.focus();
    }
}

function sfm_enable_show_msgs_together()
{
    this.show_errors_together=true;
    this.formobj.show_errors_together=true;
}
function clear_all_validations()
{
	for(var itr=0;itr < this.formobj.elements.length;itr++)
	{
		this.formobj.elements[itr].validationset = null;
	}
}

function form_submit_handler()
{
   var bRet = true;
    document.error_disp_handler.clear_msgs();
	for(var itr=0;itr < this.elements.length;itr++)
	{
		if(this.elements[itr].validationset &&
	   !this.elements[itr].validationset.validate())
		{
		  bRet = false;
		}
        if(!bRet && !this.show_errors_together)
        {
          break;

        }
	}

	if(this.addnlvalidation)
	{
	  str =" var ret = "+this.addnlvalidation+"()";
	  eval(str);

     if(!ret) 
     {
       bRet=false; 
     }

	}

   if(!bRet)
    {
      document.error_disp_handler.FinalShowMsg();
      return false;
    }
	return true;
}

function add_validation(itemname,descriptor,errstr)
{
	var condition = null;
	if(arguments.length > 3)
	{
	 condition = arguments[3]; 
	}
  if(!this.formobj)
	{
		alert("Error: The form object is not set properly");
		return;
	}//if
	var itemobj = this.formobj[itemname];
    if(itemobj.length && isNaN(itemobj.selectedIndex) )
    //for radio button; don't do for 'select' item
	{
		itemobj = itemobj[0];
	}	
  if(!itemobj)
	{
		alert("Error: Couldnot get the input object named: "+itemname);
		return;
	}
	if(!itemobj.validationset)
	{
		itemobj.validationset = new ValidationSet(itemobj,this.show_errors_together);
	}
	itemobj.validationset.add(descriptor,errstr,condition);
    itemobj.validatorobj=this;
}
function validator_enable_OPED()
{
    document.error_disp_handler.EnableOnPageDisplay(false);
}

function validator_enable_OPED_SB()
{
	document.error_disp_handler.EnableOnPageDisplay(true);
}
function sfm_ErrorDisplayHandler()
{
  this.msgdisplay = new AlertMsgDisplayer();
  this.EnableOnPageDisplay= edh_EnableOnPageDisplay;
  this.ShowMsg=edh_ShowMsg;
  this.FinalShowMsg=edh_FinalShowMsg;
  this.all_msgs=new Array();
  this.clear_msgs=edh_clear_msgs;
}
function edh_clear_msgs()
{
    this.msgdisplay.clearmsg(this.all_msgs);
    this.all_msgs = new Array();
}
function edh_FinalShowMsg()
{
    this.msgdisplay.showmsg(this.all_msgs);
}
function edh_EnableOnPageDisplay(single_box)
{
	if(true == single_box)
	{
		this.msgdisplay = new SingleBoxErrorDisplay();
	}
	else
	{
		this.msgdisplay = new DivMsgDisplayer();		
	}
}
function edh_ShowMsg(msg,input_element)
{
	
   var objmsg = new Array();
   objmsg["input_element"] = input_element;
   objmsg["msg"] =  msg;
   this.all_msgs.push(objmsg);
}
function AlertMsgDisplayer()
{
  this.showmsg = alert_showmsg;
  this.clearmsg=alert_clearmsg;
}
function alert_clearmsg(msgs)
{

}
function alert_showmsg(msgs)
{
    var whole_msg="";
    var first_elmnt=null;
    for(var m=0;m < msgs.length;m++)
    {
        if(null == first_elmnt)
        {
            first_elmnt = msgs[m]["input_element"];
        }
        whole_msg += msgs[m]["msg"] + "\n";
    }
	
    alert(whole_msg);

    if(null != first_elmnt)
    {
        sfm_set_focus(first_elmnt);
    }
}
function sfm_show_error_msg(msg,input_elmt)
{
    document.error_disp_handler.ShowMsg(msg,input_elmt);
}
function SingleBoxErrorDisplay()
{
 this.showmsg=sb_div_showmsg;
 this.clearmsg=sb_div_clearmsg;
}

function sb_div_clearmsg(msgs)
{
	var divname = form_error_div_name(msgs);
	show_div_msg(divname,"");
}

function sb_div_showmsg(msgs)
{
	var whole_msg="<ul>\n";
	for(var m=0;m < msgs.length;m++)
    {
        whole_msg += "<li>" + msgs[m]["msg"] + "</li>\n";
    }
	whole_msg += "</ul>";
	var divname = form_error_div_name(msgs);
	show_div_msg(divname,whole_msg);
}
function form_error_div_name(msgs)
{
	var input_element= null;

	for(var m in msgs)
	{
	 input_element = msgs[m]["input_element"];
	 if(input_element){break;}
	}

	var divname ="";
	if(input_element)
	{
	 divname = input_element.form._sfm_form_name + "_errorloc";
	}

	return divname;
}
function DivMsgDisplayer()
{
 this.showmsg=div_showmsg;
 this.clearmsg=div_clearmsg;
}
function div_clearmsg(msgs)
{
    for(var m in msgs)
    {
        var divname = element_div_name(msgs[m]["input_element"]);
        show_div_msg(divname,"");
    }
}
function element_div_name(input_element)
{
  var divname = input_element.form._sfm_form_name + "_" + 
                   input_element.name + "_errorloc";

  divname = divname.replace(/[\[\]]/gi,"");

  return divname;
}
function div_showmsg(msgs)
{
    var whole_msg;
    var first_elmnt=null;
    for(var m in msgs)
    {
        if(null == first_elmnt)
        {
            first_elmnt = msgs[m]["input_element"];
        }
        var divname = element_div_name(msgs[m]["input_element"]);
        show_div_msg(divname,msgs[m]["msg"]);
    }
    if(null != first_elmnt)
    {
        sfm_set_focus(first_elmnt);
    }
}
function show_div_msg(divname,msgstring)
{
	if(divname.length<=0) return false;

	if(document.layers)
	{
		divlayer = document.layers[divname];
        if(!divlayer){return;}
		divlayer.document.open();
		divlayer.document.write(msgstring);
		divlayer.document.close();
	}
	else
	if(document.all)
	{
		divlayer = document.all[divname];
        if(!divlayer){return;}
		divlayer.innerHTML=msgstring;
	}
	else
	if(document.getElementById)
	{
		divlayer = document.getElementById(divname);
        if(!divlayer){return;}
		divlayer.innerHTML =msgstring;
	}
	divlayer.style.visibility="visible";	
}

function ValidationDesc(inputitem,desc,error,condition)
{
  this.desc=desc;
	this.error=error;
	this.itemobj = inputitem;
	this.condition = condition;
	this.validate=vdesc_validate;
}
function vdesc_validate()
{
	if(this.condition != null )
	{
		if(!eval(this.condition))
		{
			return true;
		}
	}
	if(!validateInput(this.desc,this.itemobj,this.error))
	{
		this.itemobj.validatorobj.disable_validations=true;

		sfm_set_focus(this.itemobj);

		return false;
	}
	return true;
}
function ValidationSet(inputitem,msgs_together)
{
    this.vSet=new Array();
	this.add= add_validationdesc;
	this.validate= vset_validate;
	this.itemobj = inputitem;
    this.msgs_together = msgs_together;
}
function add_validationdesc(desc,error,condition)
{
  this.vSet[this.vSet.length]= 
  new ValidationDesc(this.itemobj,desc,error,condition);
}
function vset_validate()
{
    var bRet = true;
    for(var itr=0;itr<this.vSet.length;itr++)
    {
        bRet = bRet && this.vSet[itr].validate();
        if(!bRet && !this.msgs_together)
        {
            break;
        }
    }
    return bRet;
}
function validateEmail(email)
{
    var splitted = email.match("^(.+)@(.+)$");
    if(splitted == null) return false;
    if(splitted[1] != null )
    {
      var regexp_user=/^\"?[\w-_\.]*\"?$/;
      if(splitted[1].match(regexp_user) == null) return false;
    }
    if(splitted[2] != null)
    {
      var regexp_domain=/^[\w-\.]*\.[A-Za-z]{2,4}$/;
      if(splitted[2].match(regexp_domain) == null) 
      {
	    var regexp_ip =/^\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\]$/;
	    if(splitted[2].match(regexp_ip) == null) return false;
      }// if
      return true;
    }
return false;
}

function IsCheckSelected(objValue,chkValue)
{
    var selected=false;
	var objcheck = objValue.form.elements[objValue.name];
    if(objcheck.length)
	{
		var idxchk=-1;
		for(var c=0;c < objcheck.length;c++)
		{
		   if(objcheck[c].value == chkValue)
		   {
		     idxchk=c;
			 break;
		   }//if
		}//for
		if(idxchk>= 0)
		{
		  if(objcheck[idxchk].checked=="1")
		  {
		    selected=true;
		  }
		}//if
	}
	else
	{
		if(objValue.checked == "1")
		{
			selected=true;
		}//if
	}//else	

	return selected;
}
function TestDontSelectChk(objValue,chkValue,strError)
{
	var pass = true;
	pass = IsCheckSelected(objValue,chkValue)?false:true;

	if(pass==false)
	{
     if(!strError || strError.length ==0) 
        { 
        	strError = "Can't Proceed as you selected "+objValue.name;  
        }//if			  
	  sfm_show_error_msg(strError,objValue);
	  
	}
    return pass;
}
function TestShouldSelectChk(objValue,chkValue,strError)
{
	var pass = true;

	pass = IsCheckSelected(objValue,chkValue)?true:false;

	if(pass==false)
	{
     if(!strError || strError.length ==0) 
        { 
        	strError = "You should select "+objValue.name;  
        }//if			  
	  sfm_show_error_msg(strError,objValue);
	  
	}
    return pass;
}
function TestRequiredInput(objValue,strError)
{
 var ret = true;
 var val = objValue.value;
 val = val.replace(/^\s+|\s+$/g,"");//trim
    if(eval(val.length) == 0) 
    { 
       if(!strError || strError.length ==0) 
       { 
         strError = objValue.name + " : Required Field"; 
       }//if 
       sfm_show_error_msg(strError,objValue); 
       ret=false; 
    }//if 
return ret;
}
function TestMaxLen(objValue,strMaxLen,strError)
{
 var ret = true;
    if(eval(objValue.value.length) > eval(strMaxLen)) 
    { 
      if(!strError || strError.length ==0) 
      { 
        strError = objValue.name + " : "+ strMaxLen +" characters maximum "; 
      }//if 
      sfm_show_error_msg(strError,objValue); 
      ret = false; 
    }//if 
return ret;
}
function TestMinLen(objValue,strMinLen,strError)
{
 var ret = true;
    if(eval(objValue.value.length) <  eval(strMinLen)) 
    { 
      if(!strError || strError.length ==0) 
      { 
        strError = objValue.name + " : " + strMinLen + " characters minimum  "; 
      }//if               
      sfm_show_error_msg(strError,objValue); 
      ret = false;   
    }//if 
return ret;
}
function TestInputType(objValue,strRegExp,strError,strDefaultError)
{
   var ret = true;

    var charpos = objValue.value.search(strRegExp); 
    if(objValue.value.length > 0 &&  charpos >= 0) 
    { 
     if(!strError || strError.length ==0) 
      { 
        strError = strDefaultError;
      }//if 
      sfm_show_error_msg(strError,objValue); 
      ret = false; 
    }//if 
 return ret;
}
function TestEmail(objValue,strError)
{
var ret = true;
     if(objValue.value.length > 0 && !validateEmail(objValue.value)	 ) 
     { 
       if(!strError || strError.length ==0) 
       { 
          strError = objValue.name+": Enter a valid Email address "; 
       }//if                                               
       sfm_show_error_msg(strError,objValue); 
       ret = false; 
     }//if 
return ret;
}
function TestLessThan(objValue,strLessThan,strError)
{
var ret = true;
	  if(isNaN(objValue.value)) 
	  { 
	    sfm_show_error_msg(objValue.name +": Should be a number ",objValue); 
	    ret = false; 
	  }//if 
	  else
	  if(eval(objValue.value) >=  eval(strLessThan)) 
	  { 
	    if(!strError || strError.length ==0) 
	    { 
	      strError = objValue.name + " : value should be less than "+ strLessThan; 
	    }//if               
	    sfm_show_error_msg(strError,objValue); 
	    ret = false;                 
	   }//if   
return ret;          
}
function TestGreaterThan(objValue,strGreaterThan,strError)
{
var ret = true;
     if(isNaN(objValue.value)) 
     { 
       sfm_show_error_msg(objValue.name+": Should be a number ",objValue); 
       ret = false; 
     }//if 
	 else
     if(eval(objValue.value) <=  eval(strGreaterThan)) 
      { 
        if(!strError || strError.length ==0) 
        { 
          strError = objValue.name + " : value should be greater than "+ strGreaterThan; 
        }//if               
        sfm_show_error_msg(strError,objValue);  
        ret = false;
      }//if  
return ret;           
}
function TestRegExp(objValue,strRegExp,strError)
{
var ret = true;
    if( objValue.value.length > 0 && 
        !objValue.value.match(strRegExp) ) 
    { 
      if(!strError || strError.length ==0) 
      { 
        strError = objValue.name+": Invalid characters found "; 
      }//if                                                               
      sfm_show_error_msg(strError,objValue); 
      ret = false;                   
    }//if 
return ret;
}
function TestDontSelect(objValue,dont_sel_index,strError)
{
var ret = true;
    if(objValue.selectedIndex == null) 
    { 
      sfm_show_error_msg("ERROR: dontselect command for non-select Item"); 
      ret =  false; 
    } 
    if(objValue.selectedIndex == eval(dont_sel_index)) 
    { 
     if(!strError || strError.length ==0) 
      { 
      strError = objValue.name+": Please Select one option "; 
      }//if                                                               
      sfm_show_error_msg(strError,objValue); 
      ret =  false;                                   
     } 
return ret;
}
function TestSelectOneRadio(objValue,strError)
{
	var objradio = objValue.form.elements[objValue.name];
	var one_selected=false;
	for(var r=0;r < objradio.length;r++)
	{
	  if(objradio[r].checked)
	  {
	  	one_selected=true;
		break;
	  }
	}
	if(false == one_selected)
	{
      if(!strError || strError.length ==0) 
       {
	    strError = "Please select one option from "+objValue.name;
	   }	
	  sfm_show_error_msg(strError,objValue);
	}
return one_selected;
}

function validateInput(strValidateStr,objValue,strError) 
{ 
    var ret = true;
    var epos = strValidateStr.search("="); 
    var  command  = ""; 
    var  cmdvalue = ""; 
    if(epos >= 0) 
    { 
     command  = strValidateStr.substring(0,epos); 
     cmdvalue = strValidateStr.substr(epos+1); 
    } 
    else 
    { 
     command = strValidateStr; 
    } 
    switch(command) 
    { 
        case "req": 
        case "required": 
         { 
		   ret = TestRequiredInput(objValue,strError)
           break;             
         }//case required 
        case "maxlength": 
        case "maxlen": 
          { 
			 ret = TestMaxLen(objValue,cmdvalue,strError)
             break; 
          }//case maxlen 
        case "minlength": 
        case "minlen": 
           { 
			 ret = TestMinLen(objValue,cmdvalue,strError)
             break; 
            }//case minlen 
        case "alnum": 
        case "alphanumeric": 
           { 
				ret = TestInputType(objValue,"[^A-Za-z0-9]",strError, 
						objValue.name+": Only alpha-numeric characters allowed ");
				break; 
           }
        case "alnum_s": 
        case "alphanumeric_space": 
           { 
				ret = TestInputType(objValue,"[^A-Za-z0-9\\s]",strError, 
						objValue.name+": Only alpha-numeric characters and space allowed ");
				break; 
           }		   
        case "num": 
        case "numeric": 
           { 
                ret = TestInputType(objValue,"[^0-9]",strError, 
						objValue.name+": Only digits allowed ");
                break;               
           }
        case "dec": 
        case "decimal": 
           { 
                ret = TestInputType(objValue,"[^0-9\.]",strError, 
						objValue.name+": Only numbers allowed ");
                break;               
           }
        case "alphabetic": 
        case "alpha": 
           { 
                ret = TestInputType(objValue,"[^A-Za-z]",strError, 
						objValue.name+": Only alphabetic characters allowed ");
                break; 
           }
        case "alphabetic_space": 
        case "alpha_s": 
           { 
                ret = TestInputType(objValue,"[^A-Za-z\\s]",strError, 
						objValue.name+": Only alphabetic characters and space allowed ");
                break; 
           }
        case "email": 
          { 
			   ret = TestEmail(objValue,strError);
               break; 
          }
        case "lt": 
        case "lessthan": 
         { 
    	      ret = TestLessThan(objValue,cmdvalue,strError);
              break; 
         }
        case "gt": 
        case "greaterthan": 
         { 
			ret = TestGreaterThan(objValue,cmdvalue,strError);
            break; 
         }//case greaterthan 
        case "regexp": 
         { 
			ret = TestRegExp(objValue,cmdvalue,strError);
           break; 
         }
        case "dontselect": 
         { 
			 ret = TestDontSelect(objValue,cmdvalue,strError)
             break; 
         }
		case "dontselectchk":
		{
			ret = TestDontSelectChk(objValue,cmdvalue,strError)
			break;
		}
		case "shouldselchk":
		{
			ret = TestShouldSelectChk(objValue,cmdvalue,strError)
			break;
		}
		case "selone_radio":
		{
			ret = TestSelectOneRadio(objValue,strError);
		    break;
		}		 
    }//switch 
	return ret;
}
function VWZ_IsListItemSelected(listname,value)
{
 for(var i=0;i < listname.options.length;i++)
 {
  if(listname.options[i].selected == true &&
   listname.options[i].value == value) 
   {
     return true;
   }
 }
 return false;
}
function VWZ_IsChecked(objcheck,value)
{
 if(objcheck.length)
 {
     for(var c=0;c < objcheck.length;c++)
     {
       if(objcheck[c].checked == "1" && 
	     objcheck[c].value == value)
       {
        return true; 
       }
     }
 }
 else
 {
  if(objcheck.checked == "1" )
   {
    return true; 
   }    
 }
 return false;
}


function DoCustomValidation()
{
  var frm = document.forms["form_detail"];
  if(frm.hotel_user_email.value != frm.hotel_user_confirm_email.value)
  {
    sfm_show_error_msg('The Email and confirm email don not match!',frm.hotel_user_email);
    return false;
  }
  else
  {
    return true;
  }
}


function DoCustomCheckCreditCard()
{
  var frm = document.forms["form_detail"];
  myCardNo = frm.hotel_reserve_cc_number.value;
  myCardType = frm.hotel_reserve_cc_type.value;
  if (checkCreditCard (myCardNo,myCardType)) {
    return true;
  } 
  else {
    sfm_show_error_msg(ccErrors[ccErrorNo],frm.hotel_reserve_cc_number);
    return false;
  }
}



/*
	Copyright (C) 2003-2009 JavaScript-Coder.com . All rights reserved.
*/


/*============================================================================*/
/*
   If a credit card number is invalid, an error reason is loaded into the 
   global ccErrorNo variable. This can be be used to index into the global error  
   string array to report the reason to the user if required:
   
   e.g. if (!checkCreditCard (number, name) alert (ccErrors(ccErrorNo);
*/

var ccErrorNo = 0;
var ccErrors = new Array ()

ccErrors [0] = "Unknown card type";
ccErrors [1] = "No card number provided";
ccErrors [2] = "Credit card number is in invalid format";
ccErrors [3] = "Credit card number is invalid";
ccErrors [4] = "Credit card number has an inappropriate number of digits";

function checkCreditCard (cardnumber, cardname) {
     
  // Array to hold the permitted card characteristics
  var cards = new Array();

  // Define the cards we support. You may add addtional card types.
  
  //  Name:      As in the selection box of the form - must be same as user's
  //  Length:    List of possible valid lengths of the card number for the card
  //  prefixes:  List of possible prefixes for the card
  //  checkdigit Boolean to say whether there is a check digit
  
  cards [0] = {name: "Visa", 
               length: "13,16", 
               prefixes: "4",
               checkdigit: true};
  cards [1] = {name: "MasterCard", 
               length: "16", 
               prefixes: "51,52,53,54,55",
               checkdigit: true};
  cards [2] = {name: "Diners Club", 
               length: "14,16", 
               prefixes: "305, 36, 38, 54,55",
               checkdigit: true};
  cards [3] = {name: "CarteBlanche", 
               length: "14", 
               prefixes: "300,301,302,303,304,305",
               checkdigit: true};
  cards [4] = {name: "American Express", 
               length: "15", 
               prefixes: "34,37",
               checkdigit: true};
  cards [5] = {name: "Discover", 
               length: "16", 
               prefixes: "6011,622,64,65",
               checkdigit: true};
  cards [6] = {name: "JCB", 
               length: "16", 
               prefixes: "35",
               checkdigit: true};
  cards [7] = {name: "enRoute", 
               length: "15", 
               prefixes: "2014,2149",
               checkdigit: true};
  cards [8] = {name: "Solo", 
               length: "16,18,19", 
               prefixes: "6334, 6767",
               checkdigit: true};
  cards [9] = {name: "Switch", 
               length: "16,18,19", 
               prefixes: "4903,4905,4911,4936,564182,633110,6333,6759",
               checkdigit: true};
  cards [10] = {name: "Maestro", 
               length: "12,13,14,15,16,18,19", 
               prefixes: "5018,5020,5038,6304,6759,6761",
               checkdigit: true};
  cards [11] = {name: "Visa Electron", 
               length: "16", 
               prefixes: "417500,4917,4913,4508,4844",
               checkdigit: true};
  cards [12] = {name: "LaserCard", 
               length: "16,17,18,19", 
               prefixes: "6304,6706,6771,6709",
               checkdigit: true};
               
  // Establish card type
  var cardType = -1;
  for (var i=0; i<cards.length; i++) {

    // See if it is this card (ignoring the case of the string)
    if (cardname.toLowerCase () == cards[i].name.toLowerCase()) {
      cardType = i;
      break;
    }
  }
  
  // If card type not found, report an error
  if (cardType == -1) {
     ccErrorNo = 0;
     return false; 
  }
   
  // Ensure that the user has provided a credit card number
  if (cardnumber.length == 0)  {
     ccErrorNo = 1;
     return false; 
  }
    
  // Now remove any spaces from the credit card number
  cardnumber = cardnumber.replace (/\s/g, "");
  
  // Check that the number is numeric
  var cardNo = cardnumber
  var cardexp = /^[0-9]{13,19}$/;
  if (!cardexp.exec(cardNo))  {
     ccErrorNo = 2;
     return false; 
  }
       
  // Now check the modulus 10 check digit - if required
  if (cards[cardType].checkdigit) {
    var checksum = 0;                                  // running checksum total
    var mychar = "";                                   // next char to process
    var j = 1;                                         // takes value of 1 or 2
  
    // Process each digit one by one starting at the right
    var calc;
    for (i = cardNo.length - 1; i >= 0; i--) {
    
      // Extract the next digit and multiply by 1 or 2 on alternative digits.
      calc = Number(cardNo.charAt(i)) * j;
    
      // If the result is in two digits add 1 to the checksum total
      if (calc > 9) {
        checksum = checksum + 1;
        calc = calc - 10;
      }
    
      // Add the units element to the checksum total
      checksum = checksum + calc;
    
      // Switch the value of j
      if (j ==1) {j = 2} else {j = 1};
    } 
  
    // All done - if checksum is divisible by 10, it is a valid modulus 10.
    // If not, report an error.
    if (checksum % 10 != 0)  {
     ccErrorNo = 3;
     return false; 
    }
  }  

  // The following are the card-specific checks we undertake.
  var LengthValid = false;
  var PrefixValid = false; 
  var undefined; 

  // We use these for holding the valid lengths and prefixes of a card type
  var prefix = new Array ();
  var lengths = new Array ();
    
  // Load an array with the valid prefixes for this card
  prefix = cards[cardType].prefixes.split(",");
      
  // Now see if any of them match what we have in the card number
  for (i=0; i<prefix.length; i++) {
    var exp = new RegExp ("^" + prefix[i]);
    if (exp.test (cardNo)) PrefixValid = true;
  }
      
  // If it isn't a valid prefix there's no point at looking at the length
  if (!PrefixValid) {
     ccErrorNo = 3;
     return false; 
  }
    
  // See if the length is valid for this card
  lengths = cards[cardType].length.split(",");
  for (j=0; j<lengths.length; j++) {
    if (cardNo.length == lengths[j]) LengthValid = true;
  }
  
  // See if all is OK by seeing if the length was valid. We only check the 
  // length if all else was hunky dory.
  if (!LengthValid) {
     ccErrorNo = 4;
     return false; 
  };   
  
  // The credit card is in the required format.
  return true;
}
/*============================================================================*/