[eluser]PhilTem[/eluser]
Well, there are two ways to solving your problem. Number one would be something called a
MY_Controller which you kinda already created with your user-controller. However, to allow working with CI you should call it MY_Controller. Have a look at the user's guide.
Number two would be to use a library or a helper, that you autoload and then can use in every controller, model, view, library, ...