<%@ master language="C#" MasterPageFile="~/MyMasterPage.master"%>
<asp:Content ContentPlaceHolderID=MyContentPH runat="server">
   <table id="Tbl1" width="100%" height="30px" 
                    cellspacing="0" cellpadding="0">
      <tr><td width="100%" align="center" bgcolor="olive">Top</td></tr>
   </table>
   <table id="Tbl2" width="100%" height="50%" 
                    cellspacing="0" cellpadding="0">
      <tr>
         <td width="60px" align="center" bgcolor="red">Left</td>
         <td align="center">
            <asp:contentplaceholder id="MyContentPH2" runat="Server">
            </asp:contentplaceholder>    
         </td>
         <td width="60px" align="center" bgcolor="red">Right</td>
      </tr>
   </table>
   <table id="Tbl3" width="100%" height="30px"  
                    cellspacing="0" cellpadding="0">
      <tr> <td width="100%" align="center" bgcolor="olive">Bottom</td>
      </tr>
   </table>
</asp:Content>