Mira a ver si esto te sirve
<table width="434" align="center">
<tr>
<%
counter=0
Do While Not Rs.EOF
if rs("imagen")<>"" then
%>
<td colspan="4">
<div align="center"><font size="2"
color="#666666"><img src="mante/images/<%=rs("imagen")%>" vspace="0"
hspace="5" border="0"><br>
<%
Response.Write "<b><font face=Verdana size=1><b><a href="
&rs.Fields("enlace") & " target=_blank>"&rs("libro")&"</a>
</b></font><br>"%>
</font></div><br>
</td>
<%
else
%>
<td colspan="4">
<%
Response.Write "<b><font face=Verdana size=1><b><a href=" &rs.Fields
("enlace") & " target=_blank>"&rs("libro")&"</a> </b></font><br>"%>
</td>
<%
end if
counter=counter+1
Rs.MoveNext
%>
<%If counter MOd 2=0 Then
Response.Write "</tr><tr>"
Loop
%>
</table>