For this we can use the session objec($_SESSION)t. When the user login with his/ her user name and password, usually we check those to ensure for correctness. If that user name and password are valid one then we can store that user name in a session and then we can very that session variable has been set or not in a single files and we can include that file in all pages.

function checkUser()
{
//check if username exists in and session & value not equal to null
if(isset($_SESSION['username']) && $_SESSION['username']!="")
return true;
else
return false;
}

if(!checkUser())
{
header("Location:login.php");
}

If you have the better answer, then send it to us. We will display your answer after the approval.

Name :*
Email Id :*
Answer :*
Verification Code	Not readable? Load New Code
Enter the above shown code:*
	Inform me about updated answers to this question