Zen Classic Header Search Box

I have been trying to figure out how to make the submit button for the Zen Classic theme revert back to a browser generated form submit button instead of the styled link/button but cannot fins where the modification took/takes place when it is called by the theme, I've looked through all the .tpl files and it's either not there or I've missed it about 3 or 4 times.

Can you please tell me where to find this, I want the search box in the header, but not without a regular form submit button. Thanks.