When I use the code below my Windows XP OS blocks the new window. Is there a way to prevent this?

The code is written in vb.net:
Code:
Sub openNewWindow()
        Dim strScript As String = ""
        strScript = "<script>"
        strScript = strScript & "var winName= '';"
        strScript = strScript & "var w;"
        strScript = strScript & "var winFeatures = 'width=520,height=640,top=0,left=0,status,scrollbars';"
        strScript = strScript & "var winURL = 'http://www.vbdotnet.dk/abbreviations.aspx';"
        strScript = strScript & "w = window.open(winURL,winName,winFeatures);"
        strScript = strScript & "</script>"
        'Allows the alert box to be shown without wiping the controls off the page.
        Page.RegisterStartupScript("ClientScript", strScript)
    End Sub