Query regarding the 6th chapter (3rd iteration)

At the end of the 6th chapter, it instructs the readers to add ‘pid’ querystring with all the create, index and admin views. After I do so, I am getting error whenever I call update action. The error is,

"Fatal error: Call to a member function getUserOptions() on a non-object in C:\xampp\htdocs\yii_learn\protected\views\issue\_form.php on line 52"

If the _form.php file works fine with create view, wats wrong working with update view ? Also do we need to add pid querystring for the links for update and delete issues ? Please help, I am complete beginner in mvc and yii…