public boolean isAdministrativo(UsuarioDTO u) {
		Connection co = null;
		PreparedStatement pst = null;
		ResultSet rs = null;

		String bandera = null;;
		String sql = null;

		try {
			co = EscolarConnectionFactory
					.getInstance().getConnection();

			sql = "SELECT link_id, usuario, contrasena FROM usuarios where usuario=?";

			pst = co.prepareStatement(sql);
			pst.setString(1, u.getUsuario());
			rs = pst.executeQuery();

			if (rs.next()){
				bandera = rs.getString("link_id");
			}

		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				if (co != null)
					co.close();
				if (pst != null)
					pst.close();
				if (rs != null)
					rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		
		if (bandera == null)
			return true;
		else
			return false;

	}