Actionscript3: scrollBar drag area question....

Question

Hi guys...My brain is fry now and I need you guy's help

My last post http://stackoverflow.com/questions/3449725/actionscript-3-simple-drag-question

I am trying to get the scrollBar(videoSlider) dragged to the certain point base on my secondMc(container)

I have X number(dynamic) of small pics in my secondMc and I want my scrollBar stop drag after reach certain point instead of go all the way moving my secondMc to the far left....

My code is as follow:

            var singlePictureInsideSecondMcWidth:number=25;

            videoSlider.addEventListener(MouseEvent.MOUSE_DOWN, scrollMC);
        stage.addEventListener(MouseEvent.MOUSE_UP, stopScrollMC);

        buildSingleCont(videoResult);
        }

        private function scrollMC(event:MouseEvent):void{
            eventTarget = Object(event.currentTarget);
            eventTarget.startDrag(false,new Rectangle(scrollBarX,scrollBarY,contMask.width-eventTarget.width,0));
            stage.addEventListener(MouseEvent.MOUSE_MOVE, adjustCont);
        } 

        private function stopScrollMC(event:MouseEvent):void{
            stage.removeEventListener(MouseEvent.MOUSE_MOVE, adjustCont);
            eventTarget.stopDrag();
        }

        private function adjustCont(event:MouseEvent):void{
            var perct:Number=secondMc.width/secondMcMask.width;
            //var maxScroll:Number=  Not sure How to do here...

            cont.x = -eventTarget.x*perct;
        }