title: "The name does not exist in the current context"
body: <p>I get the following error;
  The name 'Request' does not exist in the current context</p>
  
  <pre><code>using System;
  using System.Web;
  using System.Web.UI;
  using System.Collections.ObjectModel;
  using System.Collections.Specialized;
  using Microsoft.Exchange.WebServices.Data;
  
  namespace Exchange101
  {
      // This sample is for demonstration purposes only. Before you run this sample, make sure that the code meets the coding requirements of your organization.
      class Ex15_CreateMeetingOnBehalfOfPrinciple_CS
      {
          static ExchangeService service = Service.ConnectToService(UserDataFromConsole.GetUserData(), new TraceListener());
          protected void Page_Load(object sender, EventArgs e)
          {
              var request = HttpContext.Current.Request.QueryString["source"];
              HttpRequest q = Request;
              NameValueCollection n = q.QueryString;
              if (n.HasKeys())
              {
                  string k = n.GetKey(0);
                  if (k == "one")
                  {
                      string v = n.Get(0);
                  }
                  if (k == "two")
                  {
                      string v = n.Get(0);
                  }
              }
          }
  </code></pre>
  
  <p>I'm an absolute newbie and have researched the error but am confused as to which assembly I might be missing as a reference.</p>