Function            tocapkey - convert the key code to uppercase

  Syntax              int tocapkey(int k);

  Prototype in        keyboard.h

  Remarks             if the key code k is a letter, it is converted to
                      upper case.

  Return value        if the key code is a lower case letter, tocapkey
                      returns the upper case of that letter, otherwise
                      tocapkey returns the key code unchanged

  See also            inkeyc(), inkeycdv()