title: Problem with StringBuilder and JSON
body: <p>I am trying to execute this code in C#.NET to turn an SQL table into a string with proper JSON;</p>
  
  <pre><code>json.AppendFormat("Places: [{{\"AvgDate\": \"{0}\"},\"MarkerID\": \"{1}\"}]", reader["AvgDate"], reader["MarkerID"]);
  </code></pre>
  
  <p>However it won't let me use the comma separation between the {0} and {1} indexes. The following works fine;</p>
  
  <pre><code>json.AppendFormat("Places: [{{\"AvgDate\": \"{0}\"}]", reader["AvgDate"], reader["MarkerID"]);
  </code></pre>
  
  <p>What am I doing wrong?</p>