if ($opt_f eq '') {
             print "Please enter the OUTPUT filename [defaults to screen]: ";
             $output_filename = <STDIN>;     
             chomp($output_filename);
             if ($output_filename eq '') {

             } else {
                    # open(SAVOUT, ">&STDOUT"); # save the stdout fhandle
                     open(STDOUT,">" . $output_filename);
                     select(STDOUT);  # force a flush on stdout so that any output will be in sync.
                     $| = 1;
             }
     } elsif ($opt_f ne "DEFAULT") {
             $output_filename = $opt_f;
             #open(SAVOUT, ">&STDOUT"); # save the stdout fhandle
             open(STDOUT,">" . $output_filename);
             select(STDOUT);  # force a flush on stdout so that any output will be in sync.
             $| = 1;


     }