IOResult function

  DECLARATION:  IOResult

      PURPOSE:  Returns the status of the last I/O operation

         UNIT:  System

  RESULT TYPE:  Word

      REMARKS:  For IOResult to function I/O checking must be turned
                off with the directive {$I-}.  If and I/O error occurs while
                this is off, all subsequent I/O operations are ignored until
                a call is made to IOResult.  A call to IOResult clears its
                internal error flag.

                NOTE:  Error codes range from 100 to 106. See errors section.