webbrowser in visual studio 2010

private void Navigate(String address)
{
    if (String.IsNullOrEmpty(address)) return;
    if (address.Equals("about:blank")) return;
    if (!address.StartsWith("http://") &&
        !address.StartsWith("https://"))
    {
        address = "http://" + address;
    }
    try
    {
        webBrowser1.Navigate(new Uri(address));
    }
    catch (System.UriFormatException)
    {
        return;
    }
}

String URL = "";

textBox1_Click(object sender, EventArgs e)
{
     //updates the URL
     URL = textBox1.Text;
}

buttonGo_Click(object sender, EventArgs e)
{
      //changes the site
      Navigate(URL);
}