Symphony.

After narrow down to replace the code in event.contactevt.php

This is strange, because contactevt really should be in the action Array.

Right you are. Seems like serialize() ignores input fields of type submit. So you may attach it manually or just add a hidden input <input type="hidden" name="action[contactevt]"/>

I had a better luck with JQuery form plugin I'm quite curious how it could handle submit button. http://getsymphony.com/discuss/thread/63575/

Gues not. Whats wrong with adding a hidden input field? Just move the name attribute from submit input to the hidden one and you're good.

Update: Just confirm to say I got the code working with nick's JS code and your hidden input, great thanks! http://getsymphony.com/discuss/thread/65331/#position-5

With Nicks approach you don't need mine and vise versa

You're right, either $.ajax or $.post work with hidden input.

naa, I mean adding '&action[event]' manually or the hidden field one. $.post is just another shorthand method for $.ajax({type: 'post'})

Oh I see.