or better yet, don't even use <form> for things that don't submit a traditional old-style POST/GET to a server. if you're handling all your logic in javascript on the client side, OR doing everything with AJAJ [0], <form> is unnecessary and you can handle things with button.onClick -- you get to program it just like any other GUI.

[0] most people use JSON not XML so i prefer to call it AJAJ not AJAX