public void prev(string id, string tablename, HyperLink HyperLink1,string url)
        {
            string sql = "select top 1 ArticleTitle,Article_ID from "+tablename+" where Article_ID<" + id;
            string sql = "select top 1 ArticleTitle,Article_ID from "+tablename+" where Article_ID>" + id;
            DataSet ds = DbHelperSQL.Query(sql);
            if (ds.Tables[0].Rows.Count > 0)
            {
                DataRow dr = DbHelperSQL.Query(sql).Tables[0].Rows[0];
                HyperLink1.Text = DBCommon.CheckChar.CutStr(dr["ArticleTitle"].ToString(), 20);
               HyperLink1.NavigateUrl = url+"?ArticleId=" + dr["Article_ID"].ToString(); ;

            }
            else
            {
                 HyperLink1.Text = "没有上一篇！";

            }
        }