Fejl i kode

Hej.

Denne kode laver fejl når man logger ind men man når ikke og se den. nogen som kan se fejlen i koden ??

<?
if (isset($login)) {

$query = mysql_query("SELECT * FROM user WHERE username='$username' AND password='". md5($_POST["password"]) ."' And status='active'");
if (mysql_num_rows($query) == "0"){
//
$login_failed = 'Dine oplysninger er ukorrekte';
//
} else {


while($user_check = mysql_fetch_array($query)) {
$s_userID = $user_check["userID"];
$s_username = $user_check["username"];
$s_password = $user_check["password"];
$s_level = $user_check["level"];
}
session_start();
session_register ("s_userID");
session_register ("s_username");
session_register ("s_password");
session_register ("s_level");

if(isset($_POST["save"])) {
    setcookie("cookie_login", yes, time()+31536000, "/"); // 1 times cookie
    setcookie("cookie_register1", $s_userID, time()+31536000, "/"); // 1 times cookie
    setcookie("cookie_register2", $s_username, time()+31536000, "/"); // 1 times cookie
    setcookie("cookie_register3", $s_password, time()+31536000, "/"); // 1 times cookie
    setcookie("cookie_register4", $s_level, time()+31536000, "/"); // 1 times cookie
}
$login = 'Du er nu logget ind';
}

$sql = mysql_query("SELECT * from user_status where userID = '$s_userID'") or die(mysql_error());
while ($update_user_status = mysql_fetch_assoc($sql)) {
$count = ($update_user_status[visit]+1);
               
    mysql_query("UPDATE user_status SET lastseen_stamp='".$timenow."', lastseen='$now()', IP='".$IP."', hostmask ='".$hostmask."', pageurl='".$onlineurl."', login_status='Online', visit='".$count."' WHERE userID='".$s_userID."'") or die(mysql_error());
    }
}
?>