HorizontalPanel hp = new HorizontalPanel();
Label lbl = new Label( constants.OverCEPWindow() );
lbl.setStyleName( "paddedLabel" );
hp.add( lbl );
cwo = new CEPWindowOperatorsDropdown( c );
cwo.addValueChangeHandler( new ValueChangeHandler<OperatorSelection>() {
public void onValueChange(ValueChangeEvent<OperatorSelection> event) {
OperatorSelection selection = event.getValue();
String selected = selection.getValue();