var initialForm = null;

$(document).ready(function() {
  checkStartCompareForm(); 
});

checkStartCompareForm = function() {
   if($('form#startComparingForm').length != 0) { //Watch the form if we find it
      initialForm = $('form#startComparingForm').serializeArray();      
      
      $('form#startComparingForm').submit(function() {
          $('form#startComparingForm input, form#startComparingForm select').css('border','0');
         var fields = $(this).serializeArray();
         var errors = false;
         
         $.each(fields, function(i, field) {
            $.each(initialForm,function(j,ifield) {
               if(ifield.name == field.name && ifield.value == field.value) {
                  errors = true;
                  $('form#startComparingForm input[name=' + field.name + '], form#startComparingForm select[name=' + field.name + ']').css('border','1px solid red');
               }
            });
         });
         
         if(errors) {
            alert('Please fill out the fields in red');
            return false;
         }
         else return true;         
      });                  
   }
};