ผมมีโค้ด useronline มีปัญหาอยู่ว่าผมใช้คุกกี้ในการจำค่า remember เลยยุ่งยากหน่อย

session_start();
$username=$_SESSION['username'];
$user= $_SESSION['user'];
$password_md5=$_SESSION['password_md5'];
$usern=$_COOKIE["username_log"];
$passs=$_COOKIE["password_log"];

include('config.inc.php');

if(($usern)){if(($user!=$usern)){$usern=$user2;}
$_SESSION['user']=$user1;
//echo $user1;
$sql="select*from userin where logname='$usern' and pw='$passs' and online='0'";
$result=mssql_query($sql);
$num_rows=mssql_num_rows($result);
if($num_rows==1)
{
$sql="update userin set online='1' where '$usern'=logname";
$result=mssql_query($sql);
$sql1="UPDATE userin SET time_login= '".time()."' WHERE logname= '$usern'";
$result1=mssql_query($sql1);

}else{
setcookie("username_log",$user,time()-3600*24*356);
setcookie("password_log",$password_md5,time()-3600*24*356);
echo "<script>alert('Login ซอน');window.location = 'home.php';</script>";exit();}}




if(isset($user)){
$sql="select*from userin where logname='$user' and pw='$password_md5' and online='0'";
$result=mssql_query($sql);
$num_rows=mssql_num_rows($result);
if($num_rows==1)
{$sql="update userin set online='1' where '$user'=logname";
$result=mssql_query($sql);
$sql1="UPDATE userin SET time_login= '".time()."' WHERE logname= '$user'";
$result1=mssql_query($sql1);

}else{echo "<script>alert('Login ซ้อน');window.location = 'home.php';</script>";exit();}}

$sql2="UPDATE userin SET online='0' WHERE time_login <='".(time()-30)."'";
$result2=mssql_query($sql2);