open(IN, "<$PATH2/dtl-file$file_id.txt") || &open_error($PATH2, "dtl-file$file_id.txt", $!);              
    open(OUT, ">>$PATH2/file1$file_id.txt") || &open_error($PATH2, "file1$file_id.txt", $!); 
                 while(<IN>){
                        print OUT $_;
                       }
     close (IN);
close (OUT);