Wait...then Fire ActionScript Code

I have a site that uses a cloud moving across the sky effect (Cloud_mc).
I’ve used the following code to move the created MC across the screen horizontally to create this moving effect.

Code:
onClipEvent(enterFrame) {
speed = -.4;
this._x += speed;

}

Problem is that once the MC runs out of clouds, the area where the clouds should be appears blank.

I need to be able to do either of the following two tasks:

  1. Play the effect for a period of time then auto-repeat the Clouds_mc

or

  1. Play the effect and then redirect to an MC that has non-moving clouds.

Thanks for your comments and assistance!

SKURGE