redirect page if permissions not meet

HI,

I am trying to dedirect a page if they do not meet the permissions to a Page.  The folowing is my persmissions statement.  Ho can I keep the message put impliment a redirect so after say 5 seconds they are redirected to my main page tha will require them to log in.  my page is (main.aspx)

If checkAdmin() = False Then

Response.Write("You do not have permission to view this page!")

Response.End()

End If
...