ActionScript 3 :: Stalling For Loop At Each Pass

I've worked out a great way to create a pixelized wipe effect, with movie clips of pixels nested in rows. I've created a loop that goes through each row, and then another loop inside that loop for the pixels in each row. I then use a random number between 1-0 for for the delay before it alpha-ups the pixel. I used Greensock for the tween and it works great. One problem, I can't stall the for loop for the rows, and every row comes up at once. Still, the pixels are staggered, and this is a nice effect, but I want it to move from left to right. So my code looks like this: (BTW, yes, AS3 does have setTimeout and it works fine)

function stripeWipeUp(stripe:MovieClip):void {
var total = stripe.numChildren;
for (var i:int = 0; i<total; i++) { // the rows
trace(i);
setTimeout(function() {
[Code] .....

What happens, with the setTimeout in there, is that the "i" for loop hits every row (there are 27) before one setTimeout gets finished. So, it doesn't work as it should - the next loop should not execute until the setTimeout is finished. How to accomplish this so each row gets stalled by about 500 ms?