Pulsing Circle

Step 1

Create a small circle and place it in the middle of your document. Press F8 and convert it to a graphic symbol.

Step 2

Now make a new layer and copy and paste that circle to this new layer. On this second layer, goto frame 20 and press F6 to insert a keyframe.

Step 3

At frame 20 of layer 2, Enlarge this circle and change the tint to any color.

Step 4

Create another keyframe at frame 40. Goto frame 1 and press Ctrl+C to copy the circle. Go back to frame 40 and Press Ctrl+V to paste it on the document. Insert a tween between frame 1-20 and 20-40. Your time line should be like this so far... small circle at frame 1, big circle at frame 20, and small circle again on frame 40. Remember that all these things are done to the second layer. Leave the first layer with just the circle alone for now.

Step 5

Goto frame 1 of your second layer and left click your circle to show its properties. Change the alpha levels to 0%. Goto frame 40 and do the same thing. Go back to layer 1 and make a keyframe at 40. Press Ctrl+Enter to see the results.

Final Result: