want an oval search button

Is it possible to make an oval search button? I found the code for searchsubmit in the style.css and played with it a bit until it was #sidebar #searchsubmit {
padding: 0px;
font-family: Verdana, Arial, Helvetica, sans-serif;
font-size: 10px;
color: #ffffff;
background-image: url(images/search.gif);
height: 30px;
width: 60px;
font-weight: bold;
}
Basically, it has white text and th search.gif gives it a multi-colored background image that I made, but it is still a rectangle.

Then I looked in WP support and found:

background: transparent url(images/submit.png) top left no-repeat;
width: 50px;
padding-left: 5px;
display:inline-block;
overflow: hidden;
/* Hack for IE */
text-indent:-9999px;
font-size: 0px;
line-height: 0px;
}

I tried this with search1.gif as my new oval Photoshop button image, instead of submit.png and have played with variations, but can’t make an oval. I would appreciate any help on this. Site is at http://www.timeforchi.com.