Sprite Gradient Mask AS3

Hi all,

This is my first post so forgive me if I make any mistakes.

I have created a Sprite that contains 3 movieclips that act as masks for another movieclip. 2 of the moviclips have an alpha gradient but I cannot get the alpha to work. I have the three masks because they are separately animated.

Here is my code.

var maskContainer = new Sprite();

maskContainer.addChild(WebPageMaskEndT_mc);
maskContainer.addChild(WebPageMaskEndB_mc);
maskContainer.addChild(WebPageMask_mc);

BackgroundImage_mc.cacheAsBitmap = true;
maskContainer.cacheAsBitmap = true;

BackgroundImage_mc.mask = maskContainer;

[COLOR=“Red”]NOTE[/COLOR]: I have also tried setting cacheAsBitmap for the 3 individual masks but no results.

Any help would be much appreciated
Thanks