MOUSE_EXTBUTTONS
ms->button |= ms->obutton & MOUSE_EXTBUTTONS;
ms.button |= ms.obutton & MOUSE_EXTBUTTONS;
#define MOUSE_BUTTONS (MOUSE_STDBUTTONS | MOUSE_EXTBUTTONS)
#define MOUSE_EXTBUTTONSCHANGED MOUSE_EXTBUTTONS
act->button |= act->obutton & MOUSE_EXTBUTTONS;
act->button |= act->obutton & MOUSE_EXTBUTTONS;