string htmlSource = webBrowser1.Document.Body.InnerHtml;
MatchCollection mc = Regex.Matches(htmlSource, "<!------------------ banners top --------------------------->(?<TagText>.*?)<!------------------ banners down --------------------------->", RegexOptions.Singleline);
string match = mc[0].Value.ToString();
var result = match.Split('>','<');
MessageBox.Show(string.Format("{0}\n{1}",result[2],result[4]));
اصلاح شد