Rain, rain go away

Hello All:

I’m using the following code to create a very cool rain effect. Problem is, I only want the rain to last about 10 seconds, then I’d like it to fade away. I can get the background to fade, but the raindrops still appear.

Anyone know how I can accomplish this?

TIA

for (i = 0; i < 50; i++)
{

 var newDrop = mcRaindrop.duplicateMovieClip ("mcRaindrop" + i,
     i);
 newDrop._x = random (350);
 newDrop._y = random (20);
 newDrop._xscale = random (100);
 newDrop._alpha = random (50);
 newDrop.gotoAndPlay (random (40) + 1);
}

for (j = i; j < i + 100; j++)
{
 var newDrop = mcRaindropSlow.duplicateMovieClip (
     "mcRaindropSlow" + j, j);
 newDrop._x = random (350);
 newDrop._y = random (20);
 newDrop._xscale = random (100);
 newDrop._alpha = random (25);
 newDrop.gotoAndPlay (random (80) + 1);
}