title: NullRefrenceException was unhandled by user code
body: <p>Code below is placed in page_Load. How I should handle this to bypass UrlReferrer when you enter page directly first time and there is no referrer? 
  What I am missing here?</p>
  
  <pre><code>    if (HttpContext.Current.Request.UrlReferrer.AbsoluteUri != null)
      {
          urlReferer = HttpContext.Current.Request.UrlReferrer.AbsoluteUri.ToString();
      }
      else
      {
          urlReferer = "";
      }
  </code></pre>