In this Macromedia Flash tutorial I will show you how to make a cool image flashing text mask effect.

1.
First of we start by typing in the text we want to add this effect to, (use black color).
In the layers panel name the layer "mask"

2.
Make a new layer just under the text layer.

Now we need to import a couple of images, I used 3 images of flowers.

3.
In the timeline make a new keyframe at frame 2 and 3, place one image in frame 1, 2 and 3.

4.
Now right click at frame 3 on the mask layer an create a new keyframe

5.
In the layers panel right click the layer called mask and choose mask so it masks the text over the image layer as shown below

Now test your flash animation movie.