javascript/asp, cant close the page properly

[MrPolite]

I want to close a page if the user doesnt include the query string. this code kinda works, the problem is that when the javascrpit code runs, IE shows me a dialogbox telling me that the page is trying to close itself. and then it asks me if I want to close it or not. But I want the code to close the window automatically, what's wrong with this:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim entryID As String = Request.QueryString.Item("entryID")
        If entryID Is Nothing Then
            Response.Write("<script>setTimeout(""self.close()"",1);</script>")
        End If
    End Sub