以下是ASP下拉菜单联级的一段代码：

<!--#include virtual="/inc/conn.asp"-->
<!--
Nclassid小类
anclassid大类
-->
<%dim count
set rs=server.createobject("adodb.recordset")
rs.open "select 大类编号,小类编号,小类名称 from 小类表 order by 小类编号 ",conn,1,1%>
<script language = "JavaScript">
var onecount;
onecount=0;
subcat = new Array();
<%
count = 0
do while not rs.eof
%>
subcat[<%=count%>] = new Array("<%= trim(rs("小类名称"))%>","<%= rs("大类编号")%>","<%= rs("小类编号")%>");
<%
count = count + 1
rs.movenext
loop
rs.close
%>
onecount=<%=count%>;
function changelocation(locationid)
{
document.myform.Nclassid.length = 0;
var locationid=locationid;
var i;
for (i=0;i < onecount; i++)
{
if (subcat[i][1] == locationid)
{
document.myform.Nclassid.options[document.myform.Nclassid.length] = new Option(subcat[i][0], subcat[i][2]);
}
}
}
</script>
<form method="POST" name="myform" action="aaa.asp">
<%
rs.open "select 大类编号,大类名称 from 大类表 order by 大类编号",conn,1,1
if rs.eof and rs.bof then
response.write "请先添加栏目。"
response.end
else
%>
大类：
<select name="anclassid" size="1" id="anclassid" onChange="changelocation(document.myform.anclassid.options[document.myform.anclassid.selectedIndex].value)">
<option selected value="<%=rs("大类编号")%>"><%=trim(rs("大类名称"))%></option>
<% dim selclass
selclass=rs("大类编号")
rs.movenext
do while not rs.eof
%>
<option value="<%=rs("大类编号")%>"><%=trim(rs("大类名称"))%></option>
<%
rs.movenext
loop
end if
rs.close
%>
</select>

小类：
<select name="Nclassid">
<%rs.open "select 小类编号,小类名称 from 小类表 where 大类编号="&selclass ,conn,1,1
if not(rs.eof and rs.bof) then
%>
<option selected value="<%=rs("小类编号")%>"><%=rs("小类名称")%></option>
<% rs.movenext
do while not rs.eof%>
<option value="<%=rs("小类编号")%>"><%=rs("小类名称")%></option>
<% rs.movenext
loop
end if
rs.close
set rs = nothing
%>
</select>
</form>