Displaying errors with red border around input text fields.

[Michael Glaz]

I have the following JavaScript to display a red border around input text 
fields:

$(document).ready(function(){
  $('#new_user').submit(function(event){
    $('.required').each(function(){
      if(!$.trim($(this).val()))
      {
        $(this).addClass('emptyField');
        event.preventDefault();
      }
    });
  });
});

The CSS for emptyField is this:
.emptyField {
  border: 2px solid red;
}



But this doesn't display a red border when I get an error.  Anyone know 
what I need to do to show the bootstrap text input boxes glowing red?