Digital Workshop

Hi there,
I wonder if anyone can help me.
I created a project some time ago in Opus that was designed for CD and worked perfectly. Now my client wants to put this project on the web. When I come to publish it for the web it comes up with a sign that says "List Box not supported". I created a few pages with list boxes on them due to alot of text for that particular page. Does anyone know of a why round this one?????