public String execute() {
		String ret = ERROR;
		Connection conn = null;
		try {
			String URL = "jdbc:mysql://localhost/bookdatabase3";
			String sql1 = new String();
			ResultSet rs, rs1 = null;
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection(URL, "root", "123456789");
			String sql = "select * from Book where ISBN='" + BookID + "'";
			PreparedStatement ps = conn.prepareStatement(sql);
			rs = ps.executeQuery();
			while (rs.next()) {
				book.setISBN(rs.getString(1));
				book.setTitle(rs.getString(2));
				book.setAuthorID(rs.getString(3));
				book.setPublisher(rs.getString(4));
				book.setPublishDate(rs.getString(5));
				book.setPrice(rs.getString(6));
				sql1 = "select * from Author where AuthorID='"
						+ rs.getString("AuthorID") + "'";
				
			}
			PreparedStatement ps1 = conn.prepareStatement(sql1);
			rs1 = ps1.executeQuery();
			while (rs1.next()) {
				author.setAuthorID(rs1.getString(1));
				author.setName(rs1.getString(2));
				author.setAge(rs1.getString(3));
				author.setCountry(rs1.getString(4));
				ret = "success";
			}
		} catch (Exception e) {
			e.printStackTrace();
			ret = ERROR;
		} finally {
			if (conn != null) {
				try {
					conn.close();
				} catch (Exception e) {
				}
			}
		}
		return ret;
	}