How can I create a search which searches 2 different databases?

I have 2 different installations of LinksSQL, (2 licences as well), they use 2 seperate databases however I would like the search.cgi to search and display results from the 2 different databases on the same page.

I.E. showing search results from the 2 databases on 1 search result page (but preferably seperatly on that one page).

How do I do this?

Thanks