package  game.utils{
	
	import flash.display.DisplayObject;
	
	/*
	burnandbass[at]gmail
	util for easy managing depths / z-index in stack of a displayObject
	Only works within display object's parent list
	*/
	
	public class DisplayUtil {

		public function DisplayUtil() {
			trace("use with static methods only!");
		}
			
		//sets the Display Object of the top of the stack
		public static function sendFront(_do:DisplayObject):void {
			_do.parent.setChildIndex(_do,_do.parent.numChildren - 1);
		}
		
		//sends @_do below @child
		public static function sendBelow(_do:DisplayObject, child:DisplayObject):void {
			_do.parent.setChildIndex(_do, _do.parent.getChildIndex(child))
		}
		
		//sets @_do above @child
		public static function sendAbove(_do:DisplayObject, child:DisplayObject):void {   
			_do.parent.setChildIndex(_do, _do.parent.getChildIndex(child));
			_do.parent.swapChildren(_do, child);
		}
		
		//sets @_do at the back of the display list stack
		public static function sendBack(_do:DisplayObject):void {               
			_do.parent.setChildIndex(_do,0);
		}

	}//end
}

package  game.utils{
	
	import flash.display.DisplayObject;
	
	/*
	burnandbass[at]gmail
	util for easy managing depths / z-index in stack of a displayObject
	Only works within display object's parent list
	*/
	
	public class DisplayUtil {

		public function DisplayUtil() {
			trace("use with static methods only!");
		}
			
		//sets the Display Object of the top of the stack
		public static function sendFront(_do:DisplayObject):void {
			_do.parent.setChildIndex(_do,_do.parent.numChildren - 1);
		}
		
		//sends @_do below @child
		public static function sendBelow(_do:DisplayObject, child:DisplayObject):void {
			_do.parent.setChildIndex(_do, _do.parent.getChildIndex(child))
		}
		
		//sets @_do above @child
		public static function sendAbove(_do:DisplayObject, child:DisplayObject):void {   
			_do.parent.setChildIndex(_do, _do.parent.getChildIndex(child));
			_do.parent.swapChildren(_do, child);
		}
		
		//sets @_do at the back of the display list stack
		public static function sendBack():void {               
			_do.parent.setChildIndex(_do,0);
		}

	}//end
}

the code is self-explanary

Util for managing DisplayObject\'s depths

ActionScript 3