//helping method for getDoctorFromDB
    public static void initialize (Connection conn) {
        try {
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("select name, password, phoneNumber, hospital, idDoctor from doctor where username="+ "\""+username+"\"");
            while (rs.next()) {
            	idDoctor= rs.getInt("idDoctor");
                name =  rs.getString("name");
                password = rs.getString("password");
                phoneNumber = rs.getInt("phoneNumber");
                hospital = rs.getString("hospital");

            }

        } catch (Exception e) {
            System.out.println("db error during select of doctor= "+e);
            return;
        }

    }