open(DATAFILEIN, "$catagory.dat") || print "Your listing is the first in this category!<br>";
	flock (DATAFILEIN, 2);
	while(<DATAFILEIN>) {
		@line_pair = split(/=/,$_);
		$time2 = $line_pair[6];
		$currenttime = time ();
		$difference = $currenttime - $time2;
		#computing the number of seconds before it expires
		$expires = $expire_after_days * 86400;
		if($difference < $expires){
			push (@temp,$_);
		}
		
	}
	flock (DATAFILEIN, 8);
	if (open(DATAFILEOUT, ">$catagory.dat") ) {
		flock (DATAFILEOUT, 2);
		print DATAFILEOUT "$time=$company_name=$email=$member1=$member1phone=$data=$expiretime=$pictureurl=$password=$website=$member2=$member2phone=$address=$citystatezip=$fax=$catlisting\n";
		print DATAFILEOUT @temp;
		userlog();