网页中实现n级树？

<!--#include file="../adovbs.inc"-->
<!--#include file="../dbconn/dbconn.asp"-->
<%
function tree(officeid)
sql="select * from officedb where officeparents='"&officeid&"'"
set rs1=conn.Execute(sql)
if rs1.bof or rs1.eof then
else
while rs1.eof=false
%>
<tr><td><input type="button" value=<%=rs1("officename")%> onclick="window.open('discdisp.asp?officeid=<%=rs1("officeid")%>','discdisp','width=640,height=480,toolbar=no,menubar=no')"></td>
<td>
<table>
<%
tree(rs1("officeid"))
%>
</table>
</td></tr>
<%
rs1.movenext
wend
end if
end function
%>
<center>
<table>
<tr>
<%
tree(0)
%>
</tr>
</table>
<table>
<tr>
<td>
<input type="button" value="&Egrave;&laquo;&Igrave;&aring;&Aacute;&ocirc;&Ntilde;&Ocirc;" onclick="window.open('discdisp.asp?officeid=0','discdisp','width=640,height=480,toolbar=no,menubar=no')">
&nbsp;&nbsp;&nbsp;
<input type="button" value="&Icirc;&Ograve;&micro;&Auml;&Aacute;&ocirc;&Ntilde;&Ocirc;" onclick="window.open('discdisp.asp?officeid=self','discdisp','width=640,height=480,toolbar=no,menubar=no')">
</td>
</tr>
</table>
</center>