HtmlNode.ElementsFlags.Remove("option");
    HtmlNode.ElementsFlags.Remove("link");
    HtmlNode.ElementsFlags.Remove("meta");
    HtmlNode.ElementsFlags.Remove("form");
    HtmlDocument html = new HtmlDocument();
    HtmlNode.ElementsFlags["input"] = HtmlElementFlag.Empty;
html.OptionWriteEmptyNodes = true;

         var ETagTable = html.CreateElement("table");
        ETagTable.InnerHtml = ChangedTagE_Str;

        /* where changedtage_str = <tr>
        <th>Reference:</th>
        <td><input type="text" id="e.reference" size="30" maxlength="32" value="" /></td>
        </tr>*/

in innerHTML is gives input as `<input type="text" id="e.crm_reference" size="30" maxlength="32" value="">`