从ASP表单中获得的数据无法插入到access的表中是为什么?

<!--#include file="conn.asp"-->
<%
on error resume next
guest_name=request("guest_name")
guest_sex=request("guest_sex")
guest_company=request("guest_company")
guest_phone=request("guest_phone")
guest_address=request("guest_address")
guest_email=request("guest_email")
guest_info=request("guest_info")

if guest_name="" or guest_phone="" or guest_info="" then
response.write("<script>alert('姓名、联系电话、反馈意见都不能为空，请填写!');history.back(-1);</script>")
response.end
else
set rs=Server.CreateObject("adodb.Recordset")
sql="select * from liuyan"
rs.open sql,conn,1,3
rs.addnew
application.Lock()
rs("guest_name")=guest_name
rs("guest_sex")=guest_sex
rs("guest_company")=guest_company