[support] OT: how to do a drop down search box?

Hello, I know this is slightly off topic, so I apologize. I didn't know where else to ask. I've got a drupal 5.1 site here: http://beta.menashalibrary.org I have a search box at the top that has a drop down. The drop down chooses what you want to search, and searches accordingly. The problem is, I have no idea how to do this. I've tried javascript, but to no avail. Basically, I need on item in the drop down to search the library's web catalog, and the other to search their drupal site. Any ideas on how I can do this? - jody