Button Click show error validation message for textbox

Hello Appian People,

Is there anyway i can show the error message if textbox is empty when clicking the button, without setting the submit field of the button to true() ?

Well, at first its kinda easy to show if the textbox is empty when the submit field = true in button. 

But I want the process where it will not set to true and still if it was clicked the empty error message will show if textbox is empty.

Is it possible? Currently this is my sample process, however seems its not working. 

UPDATE: Its okey now guys, i figured it out.  Thank