Reposition thumbs on grid

Stage.align = "TL";
var total:Number = 20;
var thumbWidth:Number = 100;
var thumbHeight:Number = 60;
buildThumbs();
function buildThumbs():Void {
	for (var i:Number = 0; i<total; i++) {
		var thumb_mc:MovieClip = this.createEmptyMovieClip("thumb"+i+"_mc", i);
		with (thumb_mc) {
			beginFill(0x222222,100);
			lineStyle(0.5,0xCCCCCC,100);
			moveTo(0,0);
			lineTo(thumbWidth,0);
			lineTo(thumbWidth,thumbHeight);
			lineTo(0,thumbHeight);
			lineTo(0,0);
		}
		var label_txt:TextField = thumb_mc.createTextField("label_txt", 0, 0, 0, 0, 0);
		label_txt.text = i+1;
		label_txt.autoSize = true;
		label_txt.textColor = 0xFFFFFF;
	}
	positionInGrid();
	Stage.addListener(this);
}
function positionInGrid():Void {
	var limit:Number = Math.floor(Stage.width/thumbWidth);
	for (var i:Number = 0; i<total; i++) {
		var thumb_mc:MovieClip = this["thumb"+i+"_mc"];
		var column:Number = i%limit;
		var row:Number = Math.floor(i/limit);
		thumb_mc._x = column*thumbWidth;
		thumb_mc._y = row*thumbHeight;
	}
}
function onResize() {
	positionInGrid();
}