public boolean updatePassWord(US user){
		Boolean isUpdatePD=null;
		connectionDB();
		String sql="update US set passWord=? where userId=?";
		try {
			ps=conn.prepareStatement(sql);
			ps.setString(1,user.getPassWord());
			ps.setLong(2, user.getUserId());
			int rows=ps.executeUpdate();
			isUpdatePD=rows>0?true:false;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			closeDB();
		}
		return isUpdatePD;
	}