Here's the relation among the 3 forms:

Form A calls Form B which is independent of it (I use Show() here).
Then Form A calls Form C which is obliged to do some operations before returning back to Form A(I use ShowDialogue() here).
But here's the problem, form C also takes up the focus of form B, so B is not independent of C. Is there anyway that B could be active when C is open? I want to do some operations on B while C is open.

Many thanks.