FLV seeking not synchronous with mouse move

Hi i’m making a simple flv player where i’m creating the seekbar to show the video playback progress.

While i drag the dragger (small rectangle to show video progress) the video frames do not update fast enough with the dragger.

mc_VideoSeekbar.mc_Drager.onPress = function() {
    this.startDrag(false, 0, 0, 250, 0);
    this.onEnterFrame = function() {
        var base = this._parent.mc_Track._width-this._width;
        var perc:Number = Math.round(this._x*100/base);
mc_VideoSeekbar.mc_Drager.onRelease = mc_VideoSeekbar.mc_Drager.onReleaseOutside=function () {
    delete this.onEnterFrame;

mc_FLVPlayback is the flash’s FLVPlayback component.

Pls suggest how can i optimise the code to show realtime video seeking?