完全用asp实现二级下拉框联动，asp实现二级菜单联动。文件内附详细源码，
部分源码预览：<select name="select1" onChange="javascript:sel();">
<option value="=====请选择=====">=====请选择===== <%
if ch1=2 then for i=1 to m
if ch3=rst("state") then
response.Write("<option value='"&rst("state")&"'selected>"&rst("state")&"") rst.MoveNext else
response.Write("<option value='"&rst("state")&"'>"&rst("state")&"") rst.MoveNext end if next else
for i=1 to m
