cache control should be easy

[germanjulian]

I have a login page which then goes to a index.php file. when I press logout I do
@session_unset();
@session_destroy();

however when I press the back button I can still get to the previous PROTECTED page which contains this code

<?php
@session_start(); 
header ("Cache-control: private, no-cache"); 
if (!isset($_SESSION["login"])) {
    header ("Location: error.html");
} 

I thought the cache control would fix this problem but it doesnt.

[germanjulian]

fixed took me 2 hours wohooo thanks for the help not

header ("Cache-control: private,no-store, no-cache,must-revalidate");