怎样与SQL数据库连接用ASP做一个三级联动菜单

建一个表fenlei，包括字段如下：
id,name,level,follow

id为标识[自动编号]
name为分类名称[字符]
level为分类级别[数字，不可为空]
follow为从属于哪个分类[数字，默认为0]

假设表中内容为：
id | name | level | follow
1 | biga | 1 | 0
2 | bigb | 1 | 0
3 | sa | 2 | 1
4 | ssa | 3 | 3

sql="select * from fenlei where level = 1 and follow =0"
set rs=conn.execute(sql)
do while not rs.eof
response.write rs("id")&"."&rs("name")&"<br>"
sql1="select * from fenlei where level = 2 and follow = "&rs("id")
set rs1=conn.execute(sql)
do while not rs1.eof
response.write rs("id")&"."&rs1("id")&"."&rs1("name")&"<br>"
sql2="select * from fenlei where level = 3 and follow = "&rs1("id")
rs2=conn.execute(sql)
do while not rs2.eof
response.write rs(&qu