scopes within CI

[eluser]ramabodhi[/eluser]
i also notice the variable is disappearing on a new server request....

in class User i have a function called setInv($user_id), when called it sets $this->inv to a db query result array...

Now if someone clicks the column title i want it to send to '/inventory/sort/'.$field.'/'.$order
and i want the sort method to sort $this->inventory then just return the view...

I'm having a hard time getting scope to work the way i want to, any help is appreciated