title: Request.ServerVariables in function
body: <pre><code>public static string Call()
  {
      string ref1 = HttpContext.Current.Request.ServerVariables["HTTP_REFERER"];
      Response.write(ref1);
  }
  
  public void Page_Load(object sender, EventArgs e)
  {
      Call()
  }
  </code></pre>
  
  <blockquote>
    <p>CS0120: An object reference is required for the non-static field,
    method, or property 'System.Web.UI.Page.Response.get'</p>
  </blockquote>