Code:
<input class='button' id='subButton' name='subForm' type='submit' value='submit' title='Activating this button validates your input and if ok, submits the form for processing. An invalid form is returned with your content in tact and error messages displayed.' tabindex='11' />
Straight off one of my pages.
Style the element in the usual way and use :hover to produce your rollover effect.
Note the bit I've highlighted.