This function is
EXPERIMENTAL. The behaviour of this function, its name, and
surrounding documentation may change without notice in a future release of PHP.
This function should be used at your own risk.
Adds the given shape to the button.
Parameters
shape
An SWFShape instance
flags
The following flags are valid:
SWFBUTTON_UP,
SWFBUTTON_OVER,
SWFBUTTON_DOWN and
SWFBUTTON_HIT.
SWFBUTTON_HIT isn't ever displayed, it defines
the hit region for the button. That is, everywhere the hit shape would
be drawn is considered a "touchable" part of the button.