Actionscript fade in/out

I am trying to figure out a way to use actionscripting to fade in and out a series of “headlines”. So far what i have is: a moviclip with a different “headline” in each frame, with a stop(); at every frame. On this instance I have the code:

onClipEvent(load) {
_alpha = 1;
diff = 5;
onClipEvent(enterFrame) {

if (_alpha >= 100|| _alpha <= 0) {
diff = -diff;
_alpha += diff;

This works fine to fade in and out the first frame, but i need a script that will know when the movie has faded in and out one time, then move to the nextFrame(); and to it again. Make sense?

Any ideas greatly appreciated!!