Need some Ajax for Support System

Hi!
In Support System when creating a ticket in the front end if the user forgot to write the Subjet or the Message is redirected to .../create-ticket/#support-system-ticket-form-wrap
I was wondering if there is a workflow to easily integrate some Ajax features to display a custom message in the frontend instead of the ugly default message "Please, insert a subject for the ticket" that is displayed in a blank page
Thanks!