threding problem - ChildForm - MDI Parent Form

Hi, I want to do that;

I open many childform in MDI Parent Form and i start a process on "childform-one" and then i actived other childform and do some process on it while "childform-one" process is continuing.

But i can't do because of freezing while one process is going on..

How can i do it by using thread?

please help.

i'm sorry for my english.

best regards