สอบถามเกี่ยวกับการเรื่องการใช้ cookie และการลบ cookie หน่อยค่ะ

<?php
ob_start();
require_once "../connectdb.php";

$strName = $_SERVER['QUERY_STRING'];

 $search_member="select * from member where usermem = '$strName'";
$query_select=mysql_query($search_member);
$check_rows=mysql_num_rows($query_select);

if($check_rows<1){
echo "<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />";
			echo "<script language='javascript'>alert('Not Found this User');</script>";
			echo "<meta http-equiv='refresh' content='0;URL=../index.php'>";
}else{
setcookie("user_invite",$strName,time()+3600*24*356);
echo "<meta http-equiv='refresh' content='0;URL=home.php'>";
}
?>

<?
$user_member = $_COOKIE["strName"];
echo "$user_member";
?>