Drag Horizontal

programming flash
1

Hi

I am using this simple code to startDrag()

drag.addEventListener(MouseEvent.MOUSE_DOWN, dragD);
stage.addEventListener(MouseEvent.MOUSE_UP, dragU);

function dragD(event:Event):void {
this.startDrag();
}

function dragU(event:Event):void {
this.stopDrag();
}

I need to drag only horizontally. Can anyone help me with this?

Thanks