[tnguy3n]

I think you can use CSS to do that job.

To replace all buttons with image, add following to .button field (Main CSS)

width: 75px;
height: 15px;
margin: 0;
border: 0;
background: transparent url(images/path/button.gif) no-repeat;

adjust width & height to your values

or to replace certain button, for example that one above

<input  type="submit" value="" style="width: 75px; height: 15px; margin: 0; border: 0; background: transparent url(images/path/button.gif) no-repeat;" />