ok,
I am new to master pages. I have created a public function called setMenu in the cs file.

I can call this function fine from about half of my pages, but when i try to call it from the other half, it won't compile and I get

'System.Web.UI.MasterPage' does not contain a definition for 'setMenu'

I'm calling it exactly the same way in all the pages. Any ideas?

ok, figured out the problem. needed the following line in the aspx page. Evidently, this makes functions from the master accessible by the content page

<%@ MasterType VirtualPath="~/MyMaster.master" %>