if(loginInfo.isLoggedIn()) {
//A�adiendo elementos al RootPanel
RootPanel rootPanel = RootPanel.get();
TabPanel tabpanel = new TabPanel();
signOutLink.setHref(loginInfo.getLogoutUrl());
buscarLibros = new BuscarLibros();
tabpanel.add(buscarLibros, "Buscar Libros");
tabpanel.add(venderLibros, "Vender Libros");
tabpanel.selectTab(0);
rootPanel.add(new HTML(loginInfo.getNickname()));
rootPanel.add(signOutLink);
rootPanel.add(tabpanel);
} else {
//A�adiendo elementos al RootPanel
RootPanel rootPanel = RootPanel.get();
TabPanel tabpanel = new TabPanel();
buscarLibros = new BuscarLibros();
loadLogin();
tabpanel.add(buscarLibros, "Buscar Libros");
tabpanel.add(loginPanel, "Inicia Sesion");
tabpanel.selectTab(0);
rootPanel.add(tabpanel);