function sortChildrenByY(container:MovieClip,  inverse:false):void {
 var i:int;
 var childList:Array = new Array();

 i = container.numChildren;

 while(i--){
 childList[i] = container.getChildAt(i);
 }

 childList.sortOn("y", Array.NUMERIC);

 if(inverse){
 childList.reverse();
 }

 i = container.numChildren;

 while(i--){
 if (childList[i] != container.getChildAt(i)){
 container.setChildIndex(childList[i], i);
 }
 }
}