Help with resizing mask in fullscreen mode

Hi I have created a drawing board using a tutorial that uses a main as file and the png encoder in cs5.5. I am creating this as an exe file to be run from a cd and am not sure how to resize the mask on the board to the size of the stage if I use fullscreen mode or allow user to resize projector by dragging corner.

I’m still really new at this so might not be clear in my instructions so please bear with me.
Due to my limitations with scripting I was unable to add the mask to the main.as file but have added it to an actions layer in the drawing board movie clip is that correct?

  • have used the following code to add the mask but don’t what else I should do to it*
board.mask = mcrecMask;
addChild(mcrecMask);

Ps using as3 in cs5.5

Thanks in advance