How to display jfreechart at specified place in jsp

I have a jsp page where i need to display the chart at specified position .But With the following codes chart is getting loaded as png image and all other css design elements of the jsp page is not displaying.... Below is my code.

DefaultPieDataset dataset = new DefaultPieDataset();

    dataset.setValue("STD", 10);
    dataset.setValue("Local", 15);
    dataset.setValue("ISD", 47);
    dataset.setValue("Inet", 20);

    JFreeChart chart = ChartFactory.createPieChart3D(
            "Calls by Type", // Title
            dataset, // Data
            true, // Yes, display the legend
            true, // No, don't display tooltips
            true // No, no URLs
            );
    PiePlot3D plot4 = (PiePlot3D) chart.getPlot();
    plot4.setForegroundAlpha(0.6f);
    plot4.setBackgroundPaint(Color.cyan);
    PiePlot piePlot = (PiePlot) chart.getPlot();
    StandardPieSectionLabelGenerator labelGenerator = new StandardPieSectionLabelGenerator("{0} {1} {2}");
    piePlot.setLabelGenerator(labelGenerator);
    piePlot.setLegendLabelGenerator(labelGenerator);
    response.setContentType("html");

    ChartUtilities.writeChartAsPNG(response.getOutputStream(), chart, 400, 300);