I couldn't find a way through Front Page 2003 to do this. Therefore I'd suggest using some CSS to do what you want. To do this follow the below steps.
1. In Front Page click the "code" button at the bottom of the window.
2. Within the code you want to paste the below code somewhere in-between the <head> </head> section.
<style type="text/css">
<!--
BODY {
background-image: url(http://www.computerhope.com/logo.gif);
background-repeat: no-repeat;
}
-->
</style>3. Once that has been done change the example url:
http://www.computerhope.com/logo.gif with the location of the image you wish to use as your background.
