Best way to build site with different type of users

Hi all, I need some suggest, advice, information that help me in a right way: I want to build a site that have different type of users, like for example "admin" and "normal user". I've a form for the authentication, when the username and password are validated I will display the right section/panel. In file auth.php I validate username and password if are right I do: set all the $_SESSION[''] that I need Now one way may be this : header("Location: index.php"); I will continue to manage all the option with: if(isset($admin_index)) or if(isset($user_section)) in the same file index.php and index.tpl Or in this way : header("Location: user/index.php"); (I'm having problem in this way because the path for smarty is not right and I receive this error: Warning: Smarty error: unable to read resource) There are other (better) solutions? Any impressions, informations, helps are appreciated. -- Massimiliano Marini - http://www.linuxtime.it/massimilianomarini/ "It's easier to invent the future than to predict it." -- Alan Kay