Actionscript 3 :: Check If A Movieclip Exists On A Specific Location Relative To Event.currentTarget?

How can I check if the stage contains a movieclip on a specific x and y location on the stage?I'm building a colour-guessing game. The purpose is to walk a path through a generated field of hexagons, each assigned a random colour (yellow, red, blue or green), based on what soundfile you hear. So if you hear "yellow", you have to click a yellow tile etc.But because I want it to be a path, and the colours of the tiles are randomly generated, I have to check which colours border the currently active tile. I literally have no idea how to do this. I thought this might work but it doesnt:

if ((this.tile.y == (event.currentTarget.y - 64)) != null) {
//add the colour of this tile to array
}

[code].....