I want to add a complete url with domain to mail to reference

<a title="Send via email" target="_blank" href="mailto:?body=Thought you might like this: <%=this.Url.PageUrl("News/Detail",new{UserKey=this.GetContent("News")["UserKey"]})%>&amp;subject=<%=this.GetContent("News")["Title"]%>">email it!</a>

But PageUrl returns absolute path like
/News/Detail/News-5

How do I get complete url or current domain name?

String.Format("http://{0}{1}", CachedData.GetApplication("Application name here").HostName, local_url);


use routing and UrlHelper extensions - the best