jquery - Flot Pie Chart with PHP -

i tried add load pie chart dynamically using flot chart , php/mysql.

this javascript code

 <script id="source" language="javascript" type="text/javascript">     function fetchdata() {    $.ajax({       url:      "test.php",       method:   "get",       datatype: "json",       success:  function(series) {          var data = [  series ];          $.plot($("#graph1"), data, {             pie: {                  show: true,                 showlabel: true             },             legend: {                 show: false              }         });       }    });     settimeout(fetchdata, 1000); }   $(function () {     $("#btn").click(function(){     fetchdata();                          });     }); 

this php code

<?php      include("db.php");     $return_arr = array();     $sql = mysql_query("select item, count(target) counter type='video' , date between '2011-02-21' , '2011-02-26' group target order id asc");     while($obj = mysql_fetch_object($sql)){         $return_arr[] = $obj;        }     echo json_encode($return_arr); ?> 

this button

<input type="submit" value="click" id="btn"/> 

this array when click button

[{"item":"final 2010","count(target)":"2"},{"item":"semi final 2009","count(target)":"3"}] 

when click button, gives me error:

an invalid or illegal string specified" code: "12 [break on error] false  

and pie chart not loading. can tell me did made wrong.

when check in firebug, array showing

[{"item":"final 2010","count(target)":"2"},{"item":"semi final 2009","count(target)":"3"}] 

but when print it, shows [object object][object object], think problem, know how fix it

thanks

i think need eval data (series)

var data    = eval("(" + series + ")"); 

that should it, think

edit

added simple replication on jsfiddle : http://jsfiddle.net/tvawl/1/