Авторизация

<?php
    if ($_POST['login'] == "admin" and $_POST['password'] == "1111")
    {
       setcookie('admin', '', time()+60*60*24*7, '/','',0,'');
       session_start();
       $_SESSION['start'] = true;
    }
?>
<?php
 if (isset($_COOKIE['admin']) or isset($_SESSION['start']))
{
!!!условие!!!
}
else 
{
?>
 <form method="post" action="admin.php" enctype="multipart/form-data">
        <h4>User ID::</h4> <input type="text" name="login" size="60"><br/>
        <h4>Password:</h4> <input type="text" name="password" size="60"><br/>
        <input type="submit" value="Login">
 </form>
<?php
}
?>

<?php
session_start();
if (isset($_POST['login'],$_POST['password'])){            
       $_SESSION['start'] = ($_POST['login'] == "admin" && $_POST['password'] == "1111");
}
 
if (!isset($_SESSION['start'])) $_SESSION['start'] =  false;
if ($_SESSION['start']) setcookie('admin', '', time()+60*60*24*7, '/','',0,''); 
 
if (isset($_COOKIE['admin']) || $_SESSION['start'])
{
   die('USLOVIE WORKS !');
}
else 
{
?>
 <form method="post" action="admin.php" enctype="multipart/form-data">
        <h4>User ID::</h4> <input type="text" name="login" size="60"><br/>
        <h4>Password:</h4> <input type="text" name="password" size="60"><br/>
        <input type="submit" value="Login">
 </form>
<?php
}
?>