eliminarI.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
FormDialogBox dialog= new FormDialogBox(id, "eliminar");
dialog.show();
}
});
usuarios.setWidget(row, 0, new Label(u.getUsuario()));
usuarios.setWidget(row, 2, modificarI);
usuarios.setWidget(row, 3, eliminarI);