title: How to pass value to the javascript on partial post back using updatePanel
body: <p>I do some query in the code behind and asign the value to a hidden field. how can I pass the same value to the Javascript. I dont want to use session as It is not updating on partial page load.</p>
  
  <p>This is the code I used:</p>
  
  <pre><code> &lt;script type="text/javascript"&gt;
      google.load("visualization", "1", { packages: ["corechart"] });
      google.setOnLoadCallback(drawChart);
       //Draw a pie
      function drawChart() {
          var data = new google.visualization.DataTable();
          data.addColumn('string', 'Task');
          data.addColumn('number', 'Hours per Day');
          data.addRows(4);
  
          data.setValue(1, 0, 'Not Received');
          data.setValue(1, 1, Value1);
          data.setValue(2, 0, 'Received');
          data.setValue(2, 1, Value2);
          data.setValue(3, 0, 'Read');
          data.setValue(3, 1, Value3);
          var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
          chart.draw(data, { width: 450,backgroundColor:'#DCDCDC', height: 300, title: 'Message Status' });
  
        // to draw a bar
          var progress1 = new RGraph.VProgress('progress1', Value4, 100);
          progress1.Set('chart.colors', [Value5]);
          progress1.Set('chart.tickmarks', false);
          progress1.Set('chart.margin', 3);
          progress1.Set('chart.tickmarks.inner', false);
          progress1.Set('chart.label.inner', true);
          progress1.Set('chart.gutter.left', 20);
          progress1.Set('chart.gutter.right', 40);
          progress1.Set('chart.tickmarks', true);
          progress1.Set('chart.units.post', '%');
          progress1.Draw();
          }           
  </code></pre>
  
  <p>The Value in the last line should be passed from the hidden field. pls give me some code example.</p>