我希望在我的php用户登录中有很多用户

我希望有一个多用户登录并将他们重定向到一个特定的文件夹，例如当我有John的用户登录时，当John登录时，它将John重定向到account_John/welcome.php，另一个是当我有一个叫Alex的用户，它转到account_Alex/welcomephp时，有人能给我一些关于的提示吗

这是我的代码：

    $password = md5(md5("agdagsjagsj".$password."77gggg77g7g7g"));
    $query = mysql_query("SELECT * FROM users WHERE username='$user'");
    $numrows = mysql_num_rows($query);
    if($numrows == 1) {
        $row = mysql_fetch_assoc($query);
        $dbid = $row['id'];
        $dbuser = $row['username'];
        $dbpass = $row['password'];         
        $dbactive = $row['active'];
        if ($password == $dbpass) {
            if($dbactive == 1) {
                $_SESSION['userid'] = $dbid;
                $_SESSION['username'] = $dbuser;
                header("Location: ./processing.php");
                }
                else
                    echo "Your account is not active you need to activate your account. $form";
            }
            else
                echo "Your Password is incorrect. $form";
    }
    else
        echo "Your Username is not listed in our database. $form";
    mysql_close();

}
else 
    echo "You enter no password. $form";

}
else
    echo "Please enter your username. $form";