thanks for ur post.. i solved..
i did changes in web config file of sharepoint page like below.. may help to someone like me...
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
<add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting" assembly="System.Web.Datavisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</controls>
</pages>
<httpHandlers>
<add path="ChartImg.axd" verb="GET, HEAD" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false" />
</httpHandlers>
<appSettings>
<add key="ChartImageHandler" value="Storage=memory;Timeout=180;Url=~/tempImages/;" />
</appSettings>
<handlers>
<add name="ChartImageHandler" preCondition="integratedMode" verb="GET,HEAD,POST" path="ChartImg.axd" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</handlers>