-- with the Empty_Mask constant
-- ANCHOR(`mousemask()',`Start_Mouse')
-- There is one difference to mousmask(): we return the value of the
-- old mask, that means the event mask value before this call.
-- with the Empty_Mask constant
-- ANCHOR(`mousemask()',`Start_Mouse')
-- There is one difference to mousmask(): we return the value of the
-- old mask, that means the event mask value before this call.