NAME: ReWrite

     USE: Prepares a file to be written. If the file does not exist,
          it is first created. If the file does exist, it is
          overwritten. An untyped file may have an optional parameter
          specifying a file buffer.  Errors are returned through
          IOResult.

     DEPENDENCY:  None

     SYNTAX: ReWrite(FileVariable : File; RecordSize : Word);