title: Get Guid with query string
body: <p>I get a Guid value in a variable like that</p>
  
  <pre><code>var getvalueGuid = db.Clients.Where(u =&gt; u.Numero_telephone == 
  TextBox_numero_telephone.Text).Select(u =&gt; u.GuID).FirstOrDefault();
  </code></pre>
  
  <p>And i would like to convert it in a query string like  that:</p>
  
  <pre><code>getvalueGuid = Request.QueryString["id"];
  </code></pre>
  
  <p>How to do?</p>