External HD and itunes

I use an external HD connected to my laptop. The problem I am having is the songs get “lost” when the drive is disconnected then I hook it back up. What can I do to make the songs accessible right away after I hook up my External drive again?

I think it has to do with the way iTunes updates the library. If you connect it and iTunes doesn’t the songs, you can try getting a program like iTunes Library Updater and force an update on your library.