function CheckRequiredFields() {
	var errormessage = new String();
	if(WithoutSelectionValue(document.form1.Title))	{errormessage += "\n\nPlease select your title.";}
	if(WithoutContent(document.form1.First_Name.value))	{errormessage += "\n\nPlease enter your first name.";}
	if(WithoutContent(document.form1.Surname.value))	{errormessage += "\n\nPlease enter your surname.";}
	if(WithoutContent(document.form1.Address1.value))	{errormessage += "\n\nPlease enter your address.";}
	if(WithoutContent(document.form1.Town_City.value))	{errormessage += "\n\nPlease enter your town or city.";}
	if(WithoutContent(document.form1.Postcode.value))	{errormessage += "\n\nPlease enter your postcode.";}
	if(WithoutContent(document.form1.Email.value))	{errormessage += "\n\nPlease enter your email address.";}
	if(WithoutCheck(document.form1.Informed_printed) && WithoutCheck(document.form1.Informed_enews))	{errormessage += "\n\nPlease select the version you would like to recieve.";}

	if(errormessage.length > 2) {
		alert('NOTE:' + errormessage);
		return false;
	}
	return true;
} 

function WithoutContent(ss) {
if(ss.length > 0) { return false; }
return true;
}

function NoneWithContent(ss) {
for(var i = 0; i < ss.length; i++) {
	if(ss[i].value.length > 0) { return false; }
	}
return true;
}

function NoneWithCheck(ss) {
for(var i = 0; i < ss.length; i++) {
	if(ss[i].checked) { return false; }
	}
return true;
}

function WithoutCheck(ss) {
if(ss.checked) { return false; }
return true;
}

function WithoutSelectionValue(ss) {
for(var i = 0; i < ss.length; i++) {
	if(ss[i].selected) {
		if(ss[i].value.length) { return false; }
		}
	}
return true;
}
function isCreditCard( CC ) {                         
if (CC.length > 19)	return (false);
sum = 0; mul = 1; l = CC.length;
for (i = 0; i < l; i++) {
   digit = CC.substring(l-i-1,l-i);
   tproduct = parseInt(digit ,10)*mul;
   if (tproduct >= 10)
		sum += (tproduct % 10) + 1;
   else
		sum += tproduct;
   if (mul == 1)
		mul++;
   else
		mul--;
}
if ((sum % 10) == 0)              
	return (true);
else
   return (false);
}