javaweb项目executeUpdate报错

//Dao中更改顾客信息方法
public void update(customer cus){
			try {
				Connection conn=DBUtil.getConnection();
				String sql="update customer set 
              cusname=?,cuspassword=?,birthday=?,telephone=?,vip=?,jifen=? where cusno=?";
				PreparedStatement prep=conn.prepareStatement(sql);
				
				prep.setString(1, cus.getCusname());
				prep.setString(2, cus.getPassword());
				prep.setString(3,cus.getBirthday());
				prep.setLong(4, cus.getTelephone());
				prep.setString(5, cus.getVip());
				prep.setDouble(6, cus.getJifen());
				prep.executeUpdate();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
//servlet中更改顾客信息
public class CusUpdateServlet extends HttpServlet {

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		Integer cusno = Integer.parseInt(request.getParameter("cusno"));
		String cusname=request.getParameter("cusname");
		String password=request.getParameter("password");
		String birthday=request.getParameter("birthday");
		long telephone=Long.parseLong(request.getParameter("telephone"));
		String vip=request.getParameter("vip");
		double jifen=Double.parseDouble(request.getParameter("jifen"));
		customer cus=new customer(cusno,cusname,password,birthday,telephone,vip,jifen);
		CusDao dao= new CusDao();
		dao.update(cus); 
		response.sendRedirect("list");
		
		
	}

 TomCat报错Statement parameter 7 not set

数数问号数量

请说明你期待什么输出， 最后出现了什么输出？