#!/usr/bin/perl

$temp=$ENV{'QUERY_STRING'};

@pairs=split(/&/,$temp);

foreach $item(@pairs) {

	($key,$content)=split (/=/,$item,1);

	$content=~tr/+/ /;

	$content=~ s/%(..)/pack("c",hex($1))/ge;

	if $key=14   $filepos=$content;
         if $key=18   $filepos=$content+10;
}


open (gbfile, "book.txt");

seek (gbfile,$filepos,0);

$i=$_;
$i=$i+1;
seek (gbfile,$filepos,0);
print gbfile $i;
close (gbfile);