JTrackBar水平拖动效果

        switch(o.direction){
            case "LEFT":
                if(position <= minPosition)
                    return;
                self.setPositionBy( -trackFrequence);
                break;
            case "RIGHT":
                if(position >= maxPosition)
                    return;
                self.setPositionBy(trackFrequence);
                break;
        }
    }

    var trackarea_click = function(evt){
        evt = window.event || evt;
        var mPos = JPos.getMousePos(evt);

        var pos_ = JPos.getAbsPos(oTrackArea);
        var w_ = parseInt(getRunStyle(oBtnPointer,"width"));        

        self.setPosition(parseInt((mPos.x - pos_.x) / preFrequenceWidth));
    }

    var createHTrackArea = function(){
        var w_ = parseInt(getRunStyle(oArrBtnLeft,"width"));
        trackAreaWidth = outlineWidth - 2 * w_;
        preFrequenceWidth = trackAreaWidth / (maxPosition - minPosition);

        oTrackArea = $c("DIV");
        oOutline.appendChild(oTrackArea);

        oTrackArea.onclick = trackarea_click;

        oTrackArea.className = "trackArea";
        oTrackArea.style.width = trackAreaWidth + "px";