AjaxControlToolkit PieChart does not show if single data value is added in ASP.Net

Dear @dharmendr, thanks for your response! But the problem is more complex than to make click on accordion's header to expand the content... in fact, I can see the piechart area, but there is no graphics on it... if I set two values different to zero, the graphics shows normally, the issue is thrown only when the piechart control tries to represent 100%....