public void onSuccess(String[] s) {
//String[] chartName = s;
String chartName = s[0];
String imageUrl = "./mbo/displayChart?filename=" + chartName;
setUrl(imageUrl);
}

public class main implements EntryPoint {
    private static ChartImageNew standardChartImageGenerated;
    final RootPanel rootPanel = RootPanel.get("nameFieldContainer");

    public void onModuleLoad() {
    standardChartImageGenerated = new ChartImageNew(opcoID,0, yearID,rootPanel1);
    rootPanel1.add(standardChartImageGenerated,120,45);
    }