vba to dismiss an IE8 or IE9 "message from webpage" popup window

In excel or word, paste the following code into a vba normal module and run it.   The code goes to a public web site and tries to lookup a school.  The website pops up a "message from webpage" dialog that warns me that the the school number is not valid.

My program can detect that popup, but how can I reliably and automatically dismiss it?

I have a workaround that uses sendkeys but about 10% of the time the popup remains.

Does anybody have a solution that does NOT require sendkeys? The ideal solution would also work when objie.visible = false.

option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Sub t1022()
Dim objie As Object
Dim i As Long
Dim htmlTable As htmlTable ' set reference to microsoft html object library
Set objie = CreateObject("InternetExplorer.Application")
objie.Visible = True

objie.navigate "http://www.slforms.universalservice.org/Form471Expert/471StatusCheck.aspx"
Do: Sleep 100: Loop While objie.busy

Set htmlTable = objie.Document.getElementsByName("txtBenId")(0)
htmlTable.Value = 12345
With objie.Document.getElementById("txtFundingYear")
    .Click
    .Value = 2013
End With

    objie.Document.getElementById("btnSearch").Click
    For i = 1 To 10
        Sleep 100
        If Not objie.busy Then Exit For
    Next i
    If objie.busy Then
        MsgBox "popup detected"
    End If

End Sub