how to create premission ..!

[eluser]Unknown[/eluser]
i mean when i login as user , i cant go to the admin page also i type the link true ,
example : my admin page like : http://localhost/exam/index.php/admin/admincp
when i am a normal user it will return some false information like : you are not admin ..! something like this ..! and when i login as admin , i can come in ..!
i have trie use session put in the admin controller

Code:

class admin extends controller
{
    
    function admin()
    {
        parent::Controller();
        if($this->session->userdata('level')==1)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

i know i was wrong , because when i type the url i can come in the admin page also i'm just a normal user ..! please help me to fix this problem ..! Thank so much ..!