getting the cookie values

[eluser]mrcoder[/eluser]
Hi,

Iam new to codeigniter i want to set cookie if user checks the remember me.

i have set the cookie like this

$usercookie=set_cookie($username, $password, '86500');

and iam now trying to get tthe cookies

$getusercookie=get_cookie($usercookie);

the cookies are setting property but iam not able to get them.iam getting the null values when iam using get_cookie .can any one tell me whats the problem in my code