Custom Control Parent Page

Hi.

I have a frame on my window which can display 1 of many different pages.

Some of the pages will have a custom control on it which will need to access the parent page.

The custom control will have a button on it which will control content on the parent page.

How do access controls on the parent page?

The button_click event will need to do something like:

myButton.parentpage.myTextBox.text = "Test"

Thanks