Error when adding control to page

[shapper]

Hello,

Inside my master page Page_Init I have the following:

1: ' pContainer
2 : Dim pContainer As New Panel
3: AddHandler pContainer.Init, AddressOf pContainer_Init
4: Page.Controls.Add(pContainer)

I get the error "The control collection cannot be modified during
DataBind, Init, Load, PreRender or Unload phases."

What am I doing wrong?

Thanks,
Miguel