Function            MMickeysMovedy - number of mickeys mouse moved
                                         vertically

  Syntax              int MMickeysMovedy(void);

  Prototype in        mousehk.h

  Remarks             determines the number of mickeys the mouse has
                      moved vertically since the last call.

                      _mouse3 contains the number of mickeys the mouse
                      has moved horizontally since the last call.

                      _mouse4 contains the number of mickeys the mouse
                      has moved vertically since the last call.

  Return value        returns the number of mickeys the mouse has moved
                      vertically since the last call.

  Note                positive values indicate down/right.

  See also            MMickeysMovedx()

  Example             see demomous.c