function CheckFields(form) {
	
   if ( form.where1.checked == false && form.where2.checked == false && form.where3.checked == false ) {
     alert("Please tick at least ONE box");
     return false;
     }
     
   if ( form.postcode.value == "") {
     alert("Please enter a post code");
     return false;
     }

return true;
}