searchPickTree.setCanSelectParentItems(true);
searchPickTree.setShowTitle(false);
searchPickTree.setDataSource(EmployeeXmlDS.getInstance());
searchPickTree.setDisplayField("Name");
searchPickTree.setValueField("EmployeeId");
searchPickTree.addChangedHandler(new ChangedHandler() {
public void onChanged(ChangedEvent event) {
Criteria c = new Criteria();
c.addCriteria("ReportsTo", (Integer)event.getValue());
employeeGrid.fetchData(c);
}