ActionScript for Flash MX: The Definitive Guide, 2nd Edition By Colin Moock
Chapter 18. ActionScript Language Reference
TextField._xmouse Property
Flash 6
horizontal location of mouse pointer, relative to the text field
read-only
theField._xmouse
Description
The floating-point _xmouse property indicates the horizontal location of the mouse pointer's hotspot, relative to the left border of theField. To obtain a consistent _xmouse coordinate that is always measured relative to the Stage, use _root._xmouse instead.