Multi Artifact main class problem

Dear Friends,

I am trying to create multi artifact in my project.Every artifacts have own and diffeent "Main class".

I created multi artifacts, but the problem is that all aritifacts assigned to single value.

when I set main class in artifact #1, other artifacts's #2, #3 's main class changed also!!!

All of them use single  MANIFEST.MF file and settings!!

what should I do?

Thanks