Thank you that worked!!! I think I may understand how to use children if you could also show how to get the img src attribute when 'this' contains:
<div class="logo"> <table width="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td height="170" align="center" valign="middle"><img src="/ images/somelogo.gif" /><br /> <a href="http://www.test.org" target="_blank">Test Logo</a></ td> </tr> </table> </div>