asp access 如何限制添加同一账户一天内重复添加信息

Question

zh=trim(request("zh"))
tdate=trim(request("tdate"))

application.lock
set rs=server.createobject("adodb.recordset")
rs.open "select * from jrecord where zh='"&zh&"' and tdate='"&tdate&"'",conn,1,3
if rs.recordcount>0 then
response.write"<script>alert('对不起！\n用户帐号已经提交过\n请重新填写!');javascript:history.go(-1);</script>"
response.end
end if

我上面这些程序问题出在哪里？请高手解答！
必须是两个条件同时满足才限制

Answer 1

tdate='"&tdate&"'改为 tdate=#"&tdate&"#