Put Search! to image

<form id=”searchform” method=”get” action=”<?php echo $PHP_SELF; ?>”>
<div>
<input type=”text” name=”s” id=”s” size=”15″ />
<input type=”submit” name=”submit” value=”<?php _e(‘Search!’); ?>” />
</div>
</form>
The search button looks like “Search!”. I was wondering, Can i replace that with a image?….
I don’t want it to be value=”<?php _e(‘search!’); ?>..I want that to be a image.