title: json.net has key method?
body: <p>If my response has key "error" I need to process error and show warning box.</p>
  
  <p>Is there "haskey" method exists in json.net?
  Like: </p>
  
  <pre><code>var x= JObject.Parse(string_my);
  if(x.HasKey["error_msg"])
      MessageBox.Show("Error!")
  </code></pre>