The problem I am facing is the I am passing values to javascript to draw a graph using session values in the code behind. When page loads it take the value from the session and creates the graph, when I do partial post back using a Update Panel and Timer, I call the method to add values to the session and it does it.

public void messsagePercentStats(object sender, EventArgs args)
    {
     ...
       if (value >= lowtarg && value < Toptarg)
            {
                vProgressColor = "'#eaa600'";
            }
            else if (value >= Toptarg)
            {
                vProgressColor = "'#86cf21'";
            }
            Session.Add("vProgressColor", vProgressColor);
            Session.Add("vProgressPercentage", "["+value+"],["+remaining+"]");
             }
     }

I use the update panel to call the above method

<asp:ScriptManager ID="smCharts" runat="server" />

        <asp:UpdatePanel runat="server" ID="Holder" OnLoad="messsagePercentStats" UpdateMode="Conditional">
            <ContentTemplate>
 <asp:Timer ID="Timer1" runat="server" Interval="5000" OnTick="Timer_Tick" />

and the timer_tick method is executed every 5 seconds

protected void Timer_Tick(object sender, EventArgs args)
    {            
          ScriptManager.RegisterStartupScript(this, this.GetType(), "key", "r.init();", true);
          ResponseMetric rm = new ResponseMetric(); 
        Holder.Update();        
    }

I use ScriptManager.RegisterStartupScript(this, this.GetType(), "key", "r.init();", true); to call the r.init() Java script method to draw the graph on post back and it works fine.

Java Script:

 var r = {  
        init : function(){  
   r = Raphael("pie"),

                    data2 = [<%= Session["vProgressPercentage"] %>];
                    axisx = ["10%", "20%"];
            r.g.txtattr.font = "12px 'Fontin Sans', Fontin-Sans, sans-serif";
             r.g.barchart(80, 25, 100, 320, data2, { stacked: true, colors: [<%= Session["vProgressColor"] %>,'#fff'] });
             axis2 = r.g.axis(94, 325, 280, 0, 100, 10, 1);
        }
        }
          window.onload = function () {
          r.init();
        };

This Java Script is not getting the new value from the session, it uses the old value when the page was loaded. How can I change the code to make sure the JS uses the latest session value.