public static string MidStrEx(string sourse, string startstr, string endstr)
        {
            string result = sourse;
            int startindex, endindex;

            startindex = sourse.IndexOf(startstr);
            if (startindex == -1)
                return result;
            string tmpstr_q = sourse.Remove(startindex + startstr.Length);
            endindex = sourse.IndexOf(endstr);
            if (endindex == -1)
                return result;
            string tmpstr_h = sourse.Substring(endindex);
            result = tmpstr_q + tmpstr_h;
            return result;
        }