title: JQPlot, JSON and 'No data specified' Error
body: <p>I am trying to use JQPlot within a VB.NET application under .NET 3.5.  On a button click, using jquery, I am trying to populate the JQPlot Chart with JSON derived data using a ASP.NET Webservices Source file (which is part of the solution).  </p>
  
  <p>The JSON data is sent by the web service but when it is presented to JQPlot I get the javascript error 'No Data Specified' which is generated by JQPlot code.  </p>
  
  <p>My code listing is as follows:</p>
  
  <p>Code to listen for the button to be clicked:</p>
  
  <pre><code>$(document).ready(function () {
   $('#&lt;%=btnASMX1.ClientID%&gt;').click(function () {
    getElectricDataJSON();
   return false;
   });
  });
  </code></pre>
  
  <p>Javascript code outside the 'document.ready' function:</p>
  
  <pre><code>function ajaxDataRenderer() {
   var ret = null;
   $.ajax({
    // have to use synchronous here, else the function 
    // will return before the data is fetched
    async: false,
    //url: url,
    type: 'POST',
    contentType: 'application/json; charset=utf-8',
    url: "AccountsService.asmx/GetJSONData",
    data: "{AccountID: " + $('#&lt;%= hiddenAccountID.ClientID%&gt;').val() + " }",
    dataType: "json",
    success: function (response) {
     var ret = response.d;
     // The following two lines just display the JSON data for testing purposes
     $('#&lt;%=outputASMX.ClientID%&gt;').empty();
     $('#&lt;%=outputASMX.ClientID%&gt;').html("&lt;div&gt;" + ret + "&lt;/div&gt;");
     return ret;
    },
    error: function (request) {
     $('#&lt;%=outputASMX.ClientID%&gt;').html("&lt;div style='color:red;'&gt;WEBSERVICE UNREACHABLE&lt;/div&gt;");
    }
   });
   return ret;
  };
  
  var jsonurl = "./jsondata.txt";
  
  function getElectricDataJSON() {
   var ret = ajaxDataRenderer();
   var plot1 = $.jqplot('chart2', jsonurl, {
   title: "AJAX JSON Data Renderer",
   dataRenderer: ret, //$.jqplot.ciParser
   dataRendererOptions: {
    unusedOptionalUrl: jsonurl
   }
  });
  }
  </code></pre>
  
  <p>The JSON data format is as follows:</p>
  
  <pre><code>[ { "todate": "2013-09-23T00:00:00", "Bill": 7095.65 }, { "todate": "2013-08-22T00:00:00", "Bill": 1137.96 }, { "todate": "2013-07-24T00:00:00", "Bill": 220429.41 }, ... ]
  </code></pre>
  
  <p>Any help or advice will be appreciated.</p>