How to make a Scream Mask in Flash

First of, head to your computer and open up the Flash Program. Make a new file and for starters, make any kind of text on your Stage. Then make another Layer, calling it Mask, and create a shape right beside the text to the left. Create a Motion Tween using the shape and in the last frame, drag the shape to the right of the ending text. Right click on your Mask Layer and scroll down to properties. Change the options to lock, and turn on Mask. Go to the properties of your 1st layer and turn on the Masked button. Play your movie then save.