javascript/asp, cant close the page properly

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:

VB Code:

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

if the Page that is open has been opened with javascript (window.open) then you will not get prompted, otherwise, you do

aha thanks... here's how I use javascript:)
I open dreamweaver, add some events/stuff, copy paste/modify the code and use it on my page:D I'm really an idiot haha, gotto learn java script.... :p you think I should just look around at some online guides? or should I buy a book?

If I need a quick answer to something I tend to just search forums or google but when I'm learning something new I always buy a book (normally a dummies book!).