import flash.events.MouseEvent;
import flash.geom.Rectangle;
import flash.display.MovieClip;
import flash.events.Event;

var rect:Rectangle;
var scrollerMinY:Number = scrollbar_mc.scroller_mc.y;
var contentMaxY:Number = content_mc.y;
 

scrollbar_mc.scroller_mc.buttonMode = true;
scrollbar_mc.scroller_mc.addEventListener(MouseEvent.MOUSE_DOWN, dragIt);

function dragIt(e:MouseEvent):void {
	rect = new Rectangle(0, 0, 0, 645);
	scrollbar_mc.scroller_mc.startDrag(false, rect);
	stage.addEventListener(MouseEvent.MOUSE_UP, dropIt);
	scrollbar_mc.scroller_mc.addEventListener(Event.ENTER_FRAME, scrollIt);
}

function dropIt(e:MouseEvent):void {
	scrollbar_mc.scroller_mc.stopDrag();
	scrollbar_mc.scroller_mc.removeEventListener(Event.ENTER_FRAME, scrollIt);
}

function scrollIt(e:Event):void {
	var scrollerRange:Number = rect.height;
	var contentRange:Number = content_mc.height - mask_mc.height;
	var percentage:Number = (scrollbar_mc.scroller_mc.y - scrollerMinY) / scrollerRange;
	var targetY:Number = contentMaxY - percentage * contentRange;
	content_mc.y = targetY;
}