var ret=""
function checkFields() {                    
if (document.regform.product.value=="") {
   document.regform.product.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.forename.value=="") {
   document.regform.forename.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.surname.value=="") {
   document.regform.surname.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.street.value=="") {
   document.regform.street.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.postcode.value=="") {
   document.regform.postcode.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.city.value=="") {
   document.regform.forename.city();
   alert("Please fill in all necessary fields.");
   return false; }
else if (document.regform.email.value=="") {
   document.regform.email.focus();
   alert("Please fill in all necessary fields.");
   return false; }
else return true;
}