public JsonResult SubmitChange()
        {
            if (!Permission.LoginedNeed(Request, Response, Session))
            {
                return(Json(false));
            }
            User user = (User)Session["user"];
            int  gid  = Convert.ToInt32(Request["gid"]);
            int  uid  = Convert.ToInt32(Request["uid"]);
            int  rank = Convert.ToInt32(Request["rank"]);

            GroupMember opInfo     = GroupView.GetGroupMember(user.uid, gid);
            GroupMember memberInfo = GroupView.GetGroupMember(uid, gid);

            if (opInfo == null || memberInfo == null ||
                rank >= 3 || rank < 0 ||
                opInfo.rank < (int)MemberRank.ADMINISTRATOR ||
                memberInfo.rank == (int)MemberRank.CREATOR)
            {
                return(Json(false));
            }

            memberInfo.rank = rank;

            return(Json(GroupView.SaveGroupMember(memberInfo)));
        }