session variable not accessable

[bishnu]

Hi all,
I am new to PHP. I have two pages login.php and index.php.
In login.php, a session is started if the user is authenticaed. The user's email is stored in a session variable, which should be accessible in index.php, but its' not being accessed.
Is this necessary to call session_register()? if it is then when should it be called?
below is the code

login.php

session.start();
$_session['email']='[e-mail]';
header('Location: index.php');
It redirects to index.php

index.php

if(isset['$SESSION['email']))
{
echo 'Email is:' . $SESSION['email'];

}

it is giving error saying "invalid index session.
please suggest me
}

[abc123]

Within index.php you also have to do session_start();

[bishnu]

Thank you abc123. Your answer solved my problem.
But I have one new problem.
Let's say I have Three files loginuser.php,index.php,and membersarea.php.
When I redirect to membersarea.php from loginuser.php, the session is working fine.
I have included membersarea.php within index.php file. and in this case it is not working and saying "undefined index email2.".

What should i do?