public void ProcessRequest(HttpContext context)
        {
            string yearString = context.Request["year"];
            int    year       = -1;

            if (yearString != null && int.TryParse(yearString, out year))
            {
                eisEntities ctx    = new eisEntities();
                var         usages = from type in ctx.retirementfundusages
                                     where type.Year == year
                                     select type;
                var usageList = usages.ToList();

                List <string>  xValues = new List <string>();
                List <decimal> yValues = new List <decimal>();

                DateTime lastUpdated = DateTime.MinValue;
                foreach (var usage in usageList)
                {
                    xValues.Add(usage.retirementfundtype.TypeName);
                    yValues.Add(usage.NumberOfUsage);
                    if (usage.LastUpdated > lastUpdated)
                    {
                        lastUpdated = usage.LastUpdated;
                    }
                }
                ColumnChart chart = new ColumnChart(xValues.ToArray());
                chart.SetLastUpdated(lastUpdated);
                chart.AddSeries("หน่วย (ล้านบาท) (คน)", SeriesChartType.Bar, yValues.ToArray());

                Series series = chart.GetSeries("หน่วย (ล้านบาท) (คน)");
                int    runner = 0;
                foreach (var usage in usageList)
                {
                    series.Points[runner].Label = "(#VALY{N0}) (" + usage.NumberOfPeople.ToString("N0") + ")";
                    runner++;
                }

                Axis xAxis = chart.GetXAxis();
                xAxis.Interval = 1;

                byte[] dataArray = chart.Render();

                string filename = "image.png";
                context.Response.ContentType = "image/png";
                context.Response.AddHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
                context.Response.OutputStream.Write(dataArray, 0, dataArray.Length);
            }
            else
            {
                context.Response.ContentType = "text/plain";
                context.Response.Write("Error: Year was not specified");
            }
        }