How to create thead and tbody in ASP.NET Table ?

asp:Table does not support these elements.

Update: As jameh’s answer reveals, the sentence above is completely wrong: the TableSection property allows to control
whether a given row goes into the table’s header, body or footer.

To elaborate on his answer, it seems you can even achieve this declaratively by setting the TableSection property in your markup, without code behind:

<asp:Table id="yourId" runat="server">
    <asp:TableHeaderRow TableSection="TableHeader">
        <!-- ... -->
    </asp:TableHeaderRow>
    <asp:TableRow>
        <!-- 'TableSection' defaults to 'TableRowSection.TableBody'. -->
        <!-- ... -->
    </asp:TableRow>
    <asp:TableRow TableSection="TableFooter">
        <!-- ... -->
    </asp:TableRow>
</asp:Table>

---

Original, now moot answer follows:

You might want to try the HtmlTable class instead:

<table id="yourId" runat="server">
    <thead>
        .
        .
        .
    </thead>
    <tbody>
        .
        .
        .
    </tbody>
</table>