anchor.diff:         
              Sfdc.canvas.byId('user').innerHTML = sr.context.user.userId;
              Sfdc.canvas.byId('param').innerHTML = signedRequestJson;
  +           
           });
   
       </script>
  
positive.code:     String yourConsumerSecret=System.getenv("CANVAS_CONSUMER_SECRET");
      //String yourConsumerSecret="1818663124211010887";
      String signedRequestJson = SignedRequest.verifyAndDecodeAsJson(signedRequest[0], yourConsumerSecret);
      <% out.print(signedRequestJson); %>
  %>
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
  
negative.code:     <h1>Hello <span id='username'></span></h1>
      
      <h3>User ID: <span id='user'></span></h3>
      <h3>Parameters: <%= signedRequestJson %></h3>
      <h3>Param: <span id='param'></span></h3>
      
  </body>
  </html>
  