INT 33,6 - Get Mouse Button Release Information

	AX = 6
	BX = 0	left button
	     1	right button


	on return:
	BX = count of button releases (0-32767), set to zero after call
	CX = horizontal position at last release
	DX = vertical position at last release
	AX = status

		│F-8│7│6│5│4│3│2│1│0│  Button status
		  │  │ │ │ │ │ │ │ └──── left button (1 = pressed)
		  │  │ │ │ │ │ │ └───── right button (1 = pressed)
		  └──┴─┴─┴─┴─┴─┴────── unused