as per reference to comment i am writing code.
in login page if login successfully.
<?php
session_start();
$_SESSION['uname']="XYZ";
?>
below Page that open after successfully login.
<?php
session_start();
if(!isset($_SESSION['uname']))
//redirect to login page here
?>
here if the session variable not set that it transferred to login page again. means page can't access without login.