The page wizard requires you to implement your own custom code. On step 1 when they hit next, you validate then save step 1s items. On step 2 then you can look up step 1s stuff by looking where that info was saved. They don't by default carry on, so here are some options.
- Save the drop down value in the users session on save so you can pull it up in there next (cookies required)
- Create a temporary table holding the values that you can query.
- Not sure if you can do this but you can try to inject into the form a post value manually and try to catch it on the load step on the 2nd page.
If you are not worried about catering to cookie disabled users then just use the session, otherwise try to get the post value passed in the form.