public _x : Number
An integer that sets the x coordinate of a button relative to the local coordinates of the parent movie clip. If a button is on the main Timeline, then its coordinate system refers to the upper left corner of the Stage as (0, 0). If the button is inside a movie clip that has transformations, the button is in the local coordinate system of the enclosing movie clip. Thus, for a movie clip rotated 90 degrees counterclockwise, the enclosed button inherits a coordinate system that is rotated 90 degrees counterclockwise. The button's coordinates refer to the registration point position.
The following example sets the coordinates of my_btn to 0 on the Stage. Create a button called my_btn and enter the following ActionScript in Frame 1 of the Timeline:
my_btn._x = 0; my_btn._y = 0;
_xscale (Button._xscale property), _y (Button._y property), _yscale (Button._yscale property)