Referencing dynamically created instances

I’m not even sure if I’ve described this problem correctly. Basically in one of my classes, I have a function that takes an array and generates a tile map from that (tile based game). Anyways, once I create my tiles, the variables used to make them are gone, since they were locally scoped, but the MovieClip instances are still in the display list (which is what I want). Now how can I reference these display objects by name? Here’s the code to generate the map, if it helps:

for(var i:uint = 0; i < mapHeight; ++i) {
for(var j:uint = 0; j < mapWidth; ++j) {
this[“t_”+i+""+j] = new tile();
mapContainer.addChild(this["t
"+i+""+j]);
this["t
"+i+""+j].x = (j*tileW);
this["t
"+i+""+j].y = (i*tileH);
this["t
"+i+"_"+j].gotoAndStop(map*[j]+1);

            }

}