Alright with the way below it is extracting only referring url like this
the extraction code :
foreach (HtmlNode link in hdDoc.DocumentNode.SelectNod
I can do it with checking the url whether containing http and if not add the domain value
That's what you should do. Html Agility Pack has nothing to help you with this:
var url = new Uri( new Uri(baseUrl).GetLeftPart(UriPartial.Path), link.Attributes["href"].Value) );