listBox.addItem(ComparatorType.EQ.getName());
listBox.addItem(ComparatorType.GE.getName());
listBox.addItem(ComparatorType.GT.getName());
listBox.addItem(ComparatorType.LE.getName());
listBox.addItem(ComparatorType.LT.getName());
listBox.addChangeHandler(new PChangeHandler() {
@Override
public void onChange(final PChangeEvent event) {