if ($#in1<0 or $#in2<0) {
                # Only one file is left...
                write2 if $#in1<0;
                write1 if $#in2<0;
        }
        elsif ($in1[2] eq $in2[1]) {
                # Matching records, merge & write 'em
                writeboth;
        }
        elsif ($in1[2] lt $in2[1]) {
                # unmatched item in file 1, write it & get next rec
                write1;
        }
        else {
                # unmatched item in file 2, write it & get next rec
                write2;
        }
}