Code:
<if condition="$lastpostinfo[lastthreadid]"><table width="100%" border="0" cellpadding="4" cellspacing="0" bgcolor="#d8e1e6">
<tr>
<td><font color="#5d6e76" size="1" face="Tahoma"><strong>Last Post:</strong>
<a href="showthread.php?$session[sessionurl]goto=newpost&t=$lastpostinfo[lastthreadid]">$lastpostinfo[lastthread]</a> @ $lastpostinfo[lastposttime]</font></td>
</tr>
</table></if>
the element "$lastpostinfo[lastthreadid]" is supposed to be empty when there is no new post... so we display the block IF it is not empty!