Masking with a movie Clip

[Archbob]

Hi,
I'm trying to work with the Mask feature in flash. It sheeps I can only mask with a shape, but once I covert the shape(like a circle) that I'm masking with into a movie Clip, it no longer works.

is there anyway to mask with a movie Clip? I need to put some code for the movement of the circle.

[hts5000]

Try this:

movieClipToBeMasked_mc.setMask(mask_mc);