open window behind browser

Question

I have a website that upon a person going to it, it checks a timestamp on the database. If the timestamp is over 4 hours old then it opens a popup winodw that runs a database import/update sub that updats the database. Then closes itself out afterward.

The reasoning for doing it this way is it allows the person browsing to continue about their business while a seperate window takes care of the update.

Right now this popup appears as the focus. Is there a way to make the popup load behind the current browser window as to not intrude the users navigation?

Here is the page_load sub of the main window.

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Page.IsPostBack Then
        Dim connStr As String = ConfigurationManager.ConnectionStrings("SNA_TRT").ConnectionString
        Dim sqlConn As SqlConnection
        sqlConn = New SqlConnection(connStr)

        sqlConn.Open()

        Dim strSQL As String = "SELECT TOP 1 [ID], [LASTREFRESH], [BYWHO] FROM [TRT_db_timer] ORDER BY [ID] Desc "
        Dim cmd As New SqlCommand(strSQL, sqlConn)
        Dim dr As SqlDataReader = cmd.ExecuteReader()

        Dim lastupdate As DateTime
        Dim currenttime As DateTime = Now()

        While dr.Read()
            lastupdate = Convert.ToDateTime(dr(ClearNullDs("LASTREFRESH")))
        End While
        dr.Close()
        sqlConn.Close()

        Dim ts As TimeSpan = currenttime.Subtract(lastupdate)
        Dim dbspan As String = ts.TotalMinutes.ToString()

        Dim dsinceup As Integer = ts.Days.ToString + 1

        'MsgBox(lastupdate)
        'MsgBox(currenttime)
        'MsgBox(dbspan)

        If dbspan > 240 Then
            bodytag.Attributes.Add("onload", "window.open('/trt/admin/importnotice.aspx?DAYS=" & dsinceup & "',null,'height=150, width=350,status=yes, resizable=no, scrollbars=no, toolbar=no,location=no,menubar=no ');")
        End If
    End If
End Sub

Answer 1

If you want the update to happen when the user arrives at the site, use AJAX or a hidden iframe. If you want the update to happen every X hours no matter if the user visits the site, use a CRON job. Popping up a window to do this will aggravate the user.

Answer 2

There are definitely better way to do this (like ajax).

But to answer your question:

function loadpopunder(){
    var popunder=window.open(/* popup window parameters */);
    popunder.blur();
    window.focus(); // focuses the main window.
}