title: Change a cookie value of a cookie that already exists
body: <p>I have a cookie called SurveyCookie. Created like so:</p>
  
  <pre><code>var cookie = new HttpCookie("SurveyCookie");
  cookie.Values["surveyPage"] = "1";
  cookie.Values["surveyId"] = "1";
  cookie.Values["surveyTitle"] = "Definietly not an NSA Survey....";
  cookie.Values["lastVisit"] = DateTime.UtcNow.ToString();
  cookie.Expires = DateTime.UtcNow.AddDays(30);
  Response.Cookies.Add(cookie);
  </code></pre>
  
  <p>Which works great. Now the problem comes when I want to change the value "surveyPage" like so.</p>
  
  <p>The below will create a new cookie which is not what I want.</p>
  
  <pre><code>int cookieValue = Convert.ToInt32(Request.Cookies["SurveyCookie"]["surveyPage"]) + 1;
  Response.Cookies["SurveyCookie"]["surveyPage"] = cookieValue.ToString();
  </code></pre>
  
  <p>Then I tried this code below which doesn't work either. The surveyPage is still 1 when it should be 2.</p>
  
  <pre><code>Request.Cookies["SurveyCookie"]["surveyPage"] = cookieValue.ToString(); 
  </code></pre>
  
  <p>Since neither of the above works what does change the cookies value for surveyPage?</p>