title: how to redirect to external url from c# controller
body: <p>I'm using a c# controller as web-service.</p>
  
  <p>In it I want to redirect the user to an external url.</p>
  
  <p>How do I do it?</p>
  
  <p>Tried:</p>
  
  <pre><code>System.Web.HttpContext.Current.Response.Redirect
  </code></pre>
  
  <p>but it didn't work.</p>