rightImg.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
myList2.transferSelectedData(myList1);
}
});
vStack.addMember(rightImg);
TransferImgButton leftImg = new TransferImgButton(TransferImgButton.LEFT);
leftImg.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
myList1.transferSelectedData(myList2);