salesDAO.updateSalesEntry(sales);
    return new ModelAndView("redirect:listBill.htm");
  }
  public ModelAndView viewPrevBill(HttpServletRequest request, HttpServletResponse response)throws Exception
  {
    ModelMap modelMap = new ModelMap();
    if(request.getParameter("billNo") !=null)
    {
      long billId=Long.parseLong(request.getParameter("billNo"));
      System.out.println(billId);
      modelMap.addAttribute("items", salesDAO.selectByBillId(billId));
    }
    
    modelMap.addAttribute("bill", new Sales());
    return new ModelAndView("prevEntry",modelMap);
  }