title: string.replace not working for me
body: <p>I have this code:</p>
  
  <pre><code>string encodedKeywordsQueryValue = HttpUtility.UrlEncode(HttpContext.Current.Request.QueryString["keywords"]);
  query = query.Replace(HttpContext.Current.Request.QueryString["keywords"], encodedKeywordsQueryValue);
  </code></pre>
  
  <p>where</p>
  
  <pre><code>HttpContext.Current.Request.QueryString["keywords"] = "abc&amp; abc"
  </code></pre>
  
  <p>and </p>
  
  <pre><code>encodedKeywordsQueryValue=abc%26+abc
  </code></pre>
  
  <p>My old string value is not getting replaced with new one.</p>
  
  <p>Can anyone suggest me to do this? I have tried combination of remove and insert methods of string but not getting desired results.</p>
  
  <p>Kindly help me with this.</p>