STOP

 Terminates program execution.  Statement format:

    STOP [disp]

    disp  Is a character constant or a string of up to
          six digits.  (Fortran 95/90 and FORTRAN 77 limit 
          digits to five.)

 If you specify the optional argument "disp", the STOP statement
 displays the contents of "disp" at your terminal, terminates
 program execution, and returns control to the operating system.

 If you do not specify a value for "disp", no message is displayed.