I was reading a blog post A refresh button for asp.net pages by Peter Van Ooijen. After understanding Peter implementation, I am not sure if I agree with the suggested implementation to refresh page. It unnecessarily requires two (instead it can be easily be done using single server trip) server trips just to refresh the a page. IMO, we can achieve page refresh action by just adding onclick attribute to button.
Or, if you want a clean instance of the page after refresh, then you can add following script to the onclick event instead.
HyperLink1.Attributes.Add("onclick", "document.location='" + Request.Url.ToString() + "'");