This is the 4th part of this Flash tutorial. Next, create another folder called "image2", aswell as a layer called mask and image.
Step 19.
We're going to do the same as we did with the 1st image but, and make a mask over the 2nd image. Drag the mask MC from the library on to the mask layer and create a key frame at frame 90. When the image1 mask has shrunk, revealing the 2nd image, the 2nd image will be visible until the image2 mask starts shrinking.
Step 20.
Create a 2nd key frame at frame 90, set the x & y position of the mask to 160, and the size to 1x1 pixel.
Step 21.
Right click inbetween frame 90 and 120, of the mask layer, to create a motion tween.