Login php help

[ff123]

hello everyone im new here.. im designing a script in my which my clients can have their own pages after logging in so i have designed three pages

1 Login HTML (Sends input to process.php)

2 process.php (

$code = $_POST['code'];
$email = $_POST['email'];
$password = $_POST['password'];


if ( $code ==111 && $password == test && $email == "test@test.com" ) {
header("ClientPage.php");
} 

3. Now when it goes to Clientpage.php this page have Hidden HTML which will be opened if password matches. but unfortunately the password does not passes along with it if Im using header("");

solution?

[ff123]

here are some more things I want to do that clientpages cannot be opened directly they have their own hidden HTML which will be opened if client enter thru Login.html then.. it should have Logout link whehn it is clicked if he hit backs he cannot access and have to go again throug login.html