title: Json AJAX not working , problem in Response?
body: <p>I have a servlet application that takes the user input from HTML form , extracts the required data from backend and makes graphs/charts and shows them to user.
  The problem I am seeing is that if user selects first option from dropdown, everything works fine, the data is extracted from backend - I can see it in the AJAX response in firebug and then its parsed by json and then maps are created.
  The data that is received from backend is (what I see in AJAX response):</p>
  
  <pre><code>{"responseStr":"[47.636597,-122.189495,0,1,47.643647,-122.212038,0,26,47.505288,-122.339112,0,1,47.622741,-122.314592,0,60,47.541612,-122.129318,0,1,47.568435,-122.161237,0,166,47.682308,-122.196004,0,2,47.666673,-122.284099,0,1,47.612953,-122.316700,0,2,47.600605,-122.322286,0,30,47.589557,-122.315608,0,27,47.636351,-122.327213,0,1,47.630270,-122.177084,2,0,47.630432,-122.140126,17,0,47.621644,-122.132080,1,3,47.630808,-122.153539,86,75,47.622367,-122.337023,495,3466,47.630886,-122.306255,1423,45,47.720287,-122.090885,255,82,47.702376,-122.093340,47,4,47.676897,-122.318752,1,0,47.760994,-122.322550,1,2,47.588854,-122.221273,1,0,39.530179,-119.818395,1,1,47.631306,-122.342762,1,0,47.737242,-122.323710,1,0,47.747054,-122.305083,2,0,47.752018,-122.316452,1,0]"}
  </code></pre>
  
  <p>This is then parsed in json via</p>
  
  <pre><code>function Respond(REQ){
    var res = JSON.parse(REQ.responseText);
    var myArr = JSON.parse(res.responseStr);
    //forward myArr for processing
  }
  </code></pre>
  
  <p>Now when the same user selects option 2, all works fine, the data is extracted from backend and I can see the following in the response</p>
  
  <pre><code>{"responseStr":"[00:00:00-01:00:00,100,30,0,01:00:00-02:00:00,100,29,0,02:00:00-03:00:00,100,34,0,03:00:00-04:00:00,100,5,0,04:00:00-05:00:00,100,7,0,05:00:00-06:00:00,100,23,0,06:00:00-07:00:00,78,29,0,07:00:00-08:00:00,48,17,0,08:00:00-09:00:00,24,35,0,09:00:00-10:00:00,18,29,0,10:00:00-11:00:00,5,28,0,11:00:00-12:00:00,45,57,0,12:00:00-13:00:00,65,69,0,13:00:00-14:00:00,64,58,0,14:00:00-15:00:00,73,46,0,15:00:00-16:00:00,72,27,0,16:00:00-17:00:00,94,9,0,17:00:00-18:00:00,69,15,0,18:00:00-19:00:00,14,9,0,19:00:00-20:00:00,25,13,0,20:00:00-21:00:00,81,38,0,21:00:00-22:00:00,53,74,0,22:00:00-23:00:00,76,55,0,23:00:00-24:00:00,89,16,0]"}
  </code></pre>
  
  <p>but when it comes to parse this via</p>
  
  <pre><code>function Respond(REQ){
     var res = JSON.parse(REQ.responseText);       
     var myArr = JSON.parse(res.responseStr);
     //forward myArr for processing
  </code></pre>
  
  <p>}
  something wrong happens at line 2 of the function and hence user does not see a chart.
  If I were to put alerts in Respond function,</p>
  
  <pre><code>function Respond(REQ){
     var res = JSON.parse(REQ.responseText);       
     alert('here');
     var myArr = JSON.parse(res.responseStr);
     alert('here2');
     //forward myArr for processing
  }
  </code></pre>
  
  <p>then I do see first alert, but not the second. However, for the first case, i see both the alerts. So there is definitely something wrong on line 2. Can someone identify this by looking at the AJAX reponse?</p>