Click on the 'Office Button' (the big round logo, top-left) to bring up the Office menu and choose 'Close'.

Thanks for the suggestion but that does not work either, because the mouse does work anywhere in a Word docuemnt other than on the title bar. Up until I click on the "X" to close verything works fine. Once I clikc on the "X" nothing happens and the mouse no longer works. It oiny occurs in Word. Once I close Word and reopen it works again until I try to close it again.