how to make scroll box in the combo box?

I decided to use combo box from http://wiki.unity3d.com/index.php?title=PopupList and there is question appeared: how to make scroll box in combo box which allow to scrolling the items listed in it?
I’m sure that someone has been done with it :smiley:
Please, help me in this matter.

Take a look at these functions:

BeginScrollView

EndScrollView