Access stage from class

1

I’ve gone through the Access to stage and root post in the AS3 Tip of the Day thread and it’s put some perspective into how things work and have changed however I just can’t get the syntax right… Here’s what i’ve got

function onUpper(event:MouseEvent):void{
	switch(holder.name){
		case "one" :
			var startx:Number = holder.x;
			var finishx:Number = holder.x+100;
			//var whichclip:MovieClip = holder;
			var whichclip:MovieClip = root.content_mc;
			//trace(whichclip);
			var xTween:Tween = new Tween(whichclip, "x", Regular.easeOut, startx, finishx, .5, true);
			trace("first one")
		break;

this is inside of my external class, basically this runs inside of a function that creates buttons which will be my navigation. the second declaration of “whichclip” is where i need help. it’s pretty obvious what i’m trying to do and what i’m doing wrong if you’re up to speed with AS3. any help is greatly appreciated. thanks.