ActionScript for Flash MX: The Definitive Guide, 2nd Edition By Colin Moock
Chapter 18. ActionScript Language Reference
MovieClip._xmouse Property
Flash 5
horizontal location of the mouse pointer
read-only
mc._xmouse
Description
The floating-point _xmouse property indicates the horizontal location of the mouse pointer's hotspot, relative to the coordinate space of mc. If mc is a main movie, _xmouse is measured from the Stage's left edge. If mc is an instance, _xmouse is measured from the instance's registration point. To obtain a consistent _xmouse coordinate that is always measured relative to the Stage, use _root._xmouse.
Example
Placing the following code on a clip causes it to follow the mouse pointer's horizontal position relative to the Stage (the clip moves left and right in a straight line):
this.onEnterFrame = function () { this._x = _level0._xmouse; }
