/// <summary>
 /// 设置版主
 /// </summary>
 /// <param name="moderator">Moderator实体类</param>
 /// <returns></returns>
 public static string SetModerator(Moderator moderator)
 {
     if (moderator.IsError)
     {
         return(moderator.GetErrorMsg());
     }
     if (isExist(moderator.ModeratorId))
     {
         return("版主编号已存在");
     }
     if (MemberManagement.IsExist(moderator.MemberId))
     {
         return("该会员账号不存在");
     }
     if (IMS.Insert(moderator) == 1)
     {
         return("设置版主成功");
     }
     else
     {
         return("设置版主失败");
     }
 }