Procedure GetPresses(Var X,Y:Word; Var Button:Byte; Var Held:Boolean;
                         Var NumTimes:Word)

    This returns the X,Y  position  of the last mouse click, which button
    is being pressed (or was pressed),  whether the button is still being
    held (Held = True)  or  has  already  been  released  (Held = False),
    and how many times the button has been clicked.

    If no mouse button is being held and no button has been pressed since
    the last check, Button = 255.