<center ><font color="red" style="font-family:华文楷体;font-size:20px"><s:property value="#session.errorMES"/></font></center>
<c:remove var="errorMES" scope="session" />










//action中返回错误信息
if(user == null){
    ValueStackUtil.setSessionAttribute("errorMES", "用户名不存在！");
      return "error";
    }else if(!u.getPassword().equals(user.getPassword())){
      ValueStackUtil.setSessionAttribute("errorMES", "密码输入错误！");
      return "error";
    }