Form Submit With Image Map?

I have an image that is the background of the search bar, and then an input field is on top of it. I want to make the right side of the image where it says "go" to be the form submit button. I made a hotspot using dreamweaver, but I can't figure out the code to make it submit the form.

http://www.foodprotect.org/CFP.php

Anybody know how to do this?

I would actually slice the image up into smaller parts and use the "go" part as an input type="image" but it can be done using javascript
onclick="document.getElementById('searchbox_013816404461231668067:7ukdsrlq2jc').submit();"