php -登录和注销网站

我正在看关于制作博客，登录和注销的教程

在登录和注销系统后，我得到了一些错误

From Those Lines in this file

header。php

<?php ob_start();?>
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
include "include/config.php";
global $tf_handle;
define("uid",$_COOKIE['uid']);
define("login",$_COOKIE['login']);
$QuerySelectU = mysqli_query($tf_handle,"SELECT * FROM user WHERE u_id ='".uid."'");
$FetchObjectU = mysqli_fetch_object($QuerySelectU);
#========================[USER]========================#
define("u_id",$FetchObjectU->u_id); // different because of cookies and Db
define("uname",$FetchObjectU->u_name);
define("uemail",$FetchObjectU->u_email);
#========================[USER]========================#
?>

index . php

<?php include"files/header.php";?>
<?php
global $tf_handle;
if(isset($_POST['login']))
{
    $u_name  = strip_tags($_POST['u_name']);    
    $u_pass  = md5($_POST['u_pass']);   
    if(empty($u_name) or empty($u_pass))
    {
        echo"
            <div class='error'>Please Fill the form</div><br />
            ";      
    }
    else
    {
        $sqlquery = mysqli_query($tf_handle,"SELECT * FROM user WHERE u_name = '".$u_name."' AND u_pass = '".$u_pass."'");
        if(mysqli_num_rows($sqlquery) > 0)
        {
            $fetchLquery = mysqli_fetch_object($sqlquery);
            $uid = $fetchLquery->u_id;
            $uname = $fetchLquery->u_name;
            $upass = $fetchLquery->u_pass;
            if($uname != $u_name AND $upass != $u_pass )
            {
                //AND $upass != $u_pass
                echo"
                <div class='error'>wrong information</div><br />
                ";  
            }
            else
            {
                setcookie("uid",$uid,time()+60*60*24);
                setcookie("login",1,time()+60*60*24);
                echo"
                <div class='error'>you be redirected to home page</div><br />
                ";
                header("Refresh: 5; url=index.php");
            }
        }
        else
        {
            echo"
                <div class='error'>Wrong Information</div><br />
                ";              
        }
    }
}

尝试打开index.php

i got some errors

注意:未定义的索引:uid在/var/www/html/blog/files/header.php第8行

注意:未定义的索引:login在/var/www/html/blog/files/header.php第13行

注意:试图获得非对象的属性在/var/www/html/blog/files/header.php的第18行

注意:试图获得非对象的属性在/var/www/html/blog/files/header.php的第19行

注意:试图获得非对象的属性在/var/www/html/blog/files/header.php的第20行

我在退出系统后得到了这些错误

Logout.php

<?php include"files/header.php";?>
<?php

if(login == 1)
{
    setcookie("uid","",time()+60*60*24);
    setcookie("login","",time()+60*60*24);  
    echo"
    <div class='error'>Done </div><br />
    ";
    header("Refresh: 5; url=index.php");
}
else
{
    echo"
    <div class='error'>Wrong Page </div><br />
    ";  
}   
?>  
<?php include"files/block.php";?>
<?php include"files/footer.php";?>