I am trying to user create user group system like facebook but i have problem with user id assignment.
My database design for users table:
username uid
You have just forgotten to place the third parameter on your call to
// missing param 3 $regg=$group_user->Create_User_group($group_name,$group_information);
Should be
$regg=$group_user->Create_User_group($group_name,$group_information, $THE_UID_PARAM);