Masking technique

Hi

I’m looking for a bit of help. How would I go about creating a mask that worked like the site shown?

http://www.donnie.tv

After the little character appears, the site loads in 4 separate sections but I’d like to know how the masking (if it is masking) works for each section.

Thanks

Lazybrown

yeah its a masking effect.

Its just a normal mask over the 3 panels, and he has the same pattern as the background in his flash file.

=)