If any fields in registration form are not filled, then that fields should show a red shadow around the text and disable the submit button until all fields are filled.
Try this in CSS
.error {
-moz-box-shadow: 1px 1px 2px 2px #F00;
-webkit-box-shadow: 1px 1px 2px 2px #F00;
box-shadow: 1px 1px 2px 2px #F00;
}
And in Script like
$('input').removeClass('error');
if(validation===true)// in case of validation error
{
$('#inputId').addClass('error');
$('#submitId').prop('disabled',true);
}
else
{
$('#submitId').prop('disabled',false);
}