JQuery Mobile ajax enabled causing client side validation not working

I am learning the JQuery Mobile framewrok and is using VS 2013 for my new project. I created a MVC 4 JQuery Mobile project. From the project I got out of the box, I click on the Login link and on that login page, I click on the Login Button, it shows the expected error messages. I want my project to be ajax enabled so I set the $.mobile.ajaxEnabled = true; and debug in VS, it hits the break point I set in the Login action in the AccountController so the client-side validation didn't work and got to the post on the server-side.

Is it by design that I can't use the built-in client-side validation when ajaxEnabled is set to true? Or is there some settings that I need to set? I need my project to be jax enabled and would like to use the built-in client side validation if possible and don't have to write custom jquery validation code.