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