executeUpdate(new Operation<Object>() {
public Object invoke (Connection conn, DatabaseLiaison liaison)
throws PersistenceException, SQLException
{
// create our modified fields mask
FieldMask mask = _utable.getFieldMask();
mask.setModified("username");
mask.setModified("password");
mask.setModified("email");
// set the password to unusable
user.password = "";
// 'disable' their email address