asp.net 在iframe 中页面跳转问题 js

/// <summary>
        /// iframe 中，弹出信息并跳转
        /// </summary>
        /// <param name="msg"></param>
        /// <param name="targetPageName"></param>
        public static void ResponseShowMsg(string msg, string targetPageName)
        {
            string str = "<script> alert('{0}');  window.parent.frames[\"sysMain\"].location.href = '{1}'; </script>";
            string Urls = HttpContext.Current.Request.Url.OriginalString;
            if (Urls.LastIndexOf('?') > 0)
            {
                Urls = Urls.Substring(0, Urls.LastIndexOf('?')).Replace(HttpContext.Current.Request.Url.Segments[HttpContext.Current.Request.Url.Segments.Length - 1], targetPageName);
            }
            else
            {
                Urls = Urls.Replace(HttpContext.Current.Request.Url.Segments[HttpContext.Current.Request.Url.Segments.Length - 1], targetPageName);
            }
            str = string.Format(str, msg, Urls);

            HttpContext.Current.Response.Write(str);
        }

protected void btnSave_Click(object sender, EventArgs e)
        {
 if (bll.RoleAdd(model, tempMs))
            {
                CmvspCommon.MessageBox.ResponseShowMsg( "保存成功！", "add.aspx");
            }
            else {
                CmvspCommon.MessageBox.Show(this, "保存失败！");
            }
}