Ivan thanks for your ideas. I'm having difficulty trying them though. I'm probably just being dense but maybe I'm not explaining it well. Also FYI, I'm trying to work in VB but I'll switch if it works better in C#.
-In my .master file I have an asp:ContentPlaceHolder
-In Sitefinity in my template, I placed the SearchBox Control.
-In ~/Sitefinity/ControlTemplates/Search/SearchBox.ascx I added the style:
input type ="button" id="searchButton" runat="server" class="sf_searchSubmit" alt="Search" style="background-image: url(http://localhost/Mysite/App_Themes/MyTheme/Images/grayarrowoff.gif); width: 22px; height: 22px; border: none">
If I go to the page load event in my master, I can't add attributes to searchButton as it doesn't exist yet.
In the original web page I'm porting, the code looked like this:
<a href="#" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('Image17','','images/grayarrowon.gif',1)"><img src="images/grayarrowoff.gif" name="Image17" width="16" height="16" border="0" align="absmiddle" id="Image17" /></a>
Thanks for your help