Hi there,

Please have a look at my code for me,
It is supposed to make most of the fields mandatory but at the moment it lets
the form go with out any credit card info... is there something obvious I have missed?

function validateForm(form)
{ 
var Card_ExpMon = form.Card_ExpMon.value;
var expyr = form.Card_ExpYear.value;
var temp = new Date();
var nowMonth  = temp.getMonth();
nowMonth ++;
var nowYear = temp.getFullYear(); 
var Card_CardType = form.Card_CardType.value;
var emailID = form.Customer_Email.value;
//alert(Card_ExpMon);
//alert(expyr);
//alert(nowMonth);
//alert(nowYear);
//alert(Card_CardType);

	if (form.Customer_Name.value == "")
	{ 
	   alert("Please Enter First Name."); 
	   form.Customer_Name.focus( ); 
	   return false; 
	}
	else if (form.Customer_Surname.value == "")
	{ 
	   alert("Please Enter Your Surname."); 
	   form.Customer_Surname.focus( ); 
	   return false; 
	}
	else if (form.Customer_Address1.value == "")
	{ 
	   alert("Please Enter Your Address."); 
	   form.Customer_Address1.focus( ); 
	   return false; 
	}
	else if (form.Customer_Town.value == "")
	{ 
	   alert("Please Enter Your Town."); 
	   form.Customer_Town.focus( ); 
	   return false; 
	}
	else if (form.Customer_County.value == "")
	{ 
	   alert("Please Enter Your County."); 
	   form.Customer_County.focus( ); 
	   return false; 
	}
	else if (form.Customer_Postcode.value == "")
	{ 
	   alert("Please Enter Your Postcode."); 
	   form.Customer_Postcode.focus( ); 
	   return false; 
	}
	else if ((form.Customer_Email.value==null)||(form.Customer_Email.value=="")){
		alert("Please Enter your Email address")
		form.Customer_Email.focus()
		return false
	}
	else if (echeck(form.Customer_Email.value)==false){
		form.Customer_Email.value=""
		form.Customer_Email.focus()
		return false
	}

	else if (form.Customer_Tel.value == "")
	{ 
	   alert("Please Enter Your Telephone Number."); 
	   form.Customer_Tel.focus( ); 
	   return false; 
	}
	else if (form.Card_Country.value == "-")
	{ 
	   alert("Please Enter Your Country."); 
	   form.Card_Country.focus( ); 
	   return false; 
	}
	else if (form.Card_CardType.value == "-")
	{ 
	   alert("Please Enter Your Card Type."); 
	   form.Card_CardType.focus( ); 
	   return false; 
	}
	else if (form.Card_Nameoncard.value == "")
	{ 
	   alert("Please Enter Name on Card.");
	   form.Card_Nameoncard.focus( ); 
	   return false; 
	}
	else if (form.Card_Cardno.value == "")
	{ 
	   alert("Please Enter Card Number."); 
	   form.Card_Cardno.focus( ); 
	   return false; 
	}
	else if (isNaN(form.Card_Cardno.value))
	{ 
	   alert("Card Number must be a valid number."); 
	   form.Card_Cardno.focus( ); 
	   return false; 
	}
	else if (form.Card_Cardno.value.length < 16)
	{ 
	   alert("Please Enter Valid Card Number with no spaces."); 
	   form.Card_Cardno.focus( ); 
	   return false; 
	}
	
	//perform verification on issue dates and verification number depending on card type
	switch(form.Card_CardType.value) { 
		case 'Switch': 
			if ((form.Card_IssueMon.value == "-" ) || (form.Card_IssueMon.value == ""))
			   {
			   //alert(form.Card_Verifyno.value);
			   alert("Enter the month your card was issued."); 
			   form.Card_IssueMon.focus( ); 
			   return false;
			   }
			else if ((form.Card_IssueYear.value == "-" ) || (form.Card_IssueYear.value == ""))
			   {
			   //alert(form.Card_Verifyno.value);
			   alert("Enter the year your card was issued."); 
			   form.Card_IssueYear.focus( ); 
			   return false;
			   }		
	    break;

		case 'MasterCard': 
	    break;
		
		case 'VisaCard': 
		break;
	}		
	if ((nowYear > expyr) || ((nowYear == expyr ) && (nowMonth > Card_ExpMon)))
	{ 
	   alert("Expiry Date has expired."); 
	   form.Card_ExpMon.focus( ); 
	   return false; 
	}
	else if (form.Card_Verifyno.value == "")
   {
	   //alert(form.Card_Verifyno.value);
	   alert("Please enter your verification number."); 
	   form.Card_Verifyno.focus( ); 
	   return false;
   }
	else if (isNaN(form.Card_Verifyno.value))
	   { 
	   alert("Your verification Number must be a valid number."); 
	   form.Card_Verifyno.focus( ); 
	   return false; 
	   }
	else if (form.Card_Verifyno.value.length != 3)
	{ 
	   alert("Your verification Number must be 3 digits."); 
	   form.Card_Verifyno.focus( ); 
	   return false; 
	}  
	else if (form.Customer_Tel.value == "")
	{ 
	   alert("Please Enter Your Telephone Number."); 
	   form.Customer_Tel.focus( ); 
	   return false; 
	}
}

//email validation function, called from within above validateForm function
function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if (str.indexOf(at)==-1){
		   alert("The E-mail that you have entered is not valid")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("The E-mail that you have entered is not valid")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("The E-mail that you have entered is not valid")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("The E-mail that you have entered is not valid")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("The E-mail that you have entered is not valid")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("The E-mail that you have entered is not valid")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("The E-mail that you have entered is not valid")
		    return false
		 }

 		 return true					
	}

Problem may not be with the function, but how you're calling it. Are you doing this:

<form action="..." method="..." onSubmit="return validateForm(this)"> ?