Automatically changing all albums to compilations in a single stroke

Is there a way to automatically change all albums in my iTunes library to compilations? After reading the discussions here and playing around in iTunes, the only way I've figured out how to create compilations is to mark each individual song by checking the "part of a compilation" box. (That check-box only appears in the info box for a single song, not in the info box for multiple songs.) However, I have over 6000 songs, and it would take a very, very long time to manually change every single one... Certainly, not every album that I have is a 'compilation', but many of them are, and I'd like to avoid (1) identifying which ones ought to be marked "compilation", and (2) manually marking every single track. If I could automatically change all albums to compilations (or automatically mark every song as "part of a compilation"), that would be the fastest and easiest way to solve the problem.

Message was edited by: samzerin