How do you create an inverse mask using AS2?

Question

Possible Duplicate:
Flash inverted mask

So here's the mask:

imageMC.setMask(maskMC);

This displays the masked area, and nothing outside of it. What I need to do is the opposite; to display only the unmasked area. I need to do this dynamically with code.

Answer 1

EDIT:

Try using the blendMode method:

// `mainMC` and `maskMC` are MovieClip objects in the FLA library.

this.attachMovie("mainMC", "main", 10);
main.attachMovie("maskMC", "punchout", 11);

main1.cacheAsBitmap = true;
main.punchout.cacheAsBitmap = true;

main.blendMode = "layer";
main.punchout.blendMode = "erase";