facebook integration problem

[eluser]Bigil Michael[/eluser]
I am trying to integrate facebook log in on my site. Follows the steps from here

Code:

http://www.dannyherran.com/2011/02/facebook-php-sdk-and-codeigniter-for-basic-user-authentication/comment-page-1/#comments

It running fine before redirection. When try to redirect it shows an error

Code:

An Error Was Encountered

The URI you submitted has disallowed characters.

permitted uri charecters given below

Code:

$config['permitted_uri_chars'] = 'a-z 0-9~%.:_\-';

can anyone help me to solve this problem???