private void DisplayFirstUrl()
{
    if (webBrowser1.Document != null)
    {
        //If this is called first, the window will only have a status bar.
        webBrowser1.Document.Window.Open(new Uri("http://www.microsoft.com/"), "displayWindow", "status=yes,width=200,height=400", false);
    }
}

private void DisplaySecondUrl()
{
    if (webBrowser1.Document != null)
    {
        // If this is called first, the window will only have an Address bar.
        webBrowser1.Document.Window.Open(new Uri("http://msdn.microsoft.com/"), "displayWindow", "width=400,height=200,location=yes", false);
    }
}