ASP中时间写入ACCESS数据库出错问题?

<%if not session("islogin") = "yes" then response.redirect("login.htm")
title = Request.Form("title")
data = Request.Form("data")
username = session("username")
set conn = server.createobject("adodb.connection")
conn.open "driver={microsoft access driver (*.mdb)};dbq="&server.mappath("bbs.mdb")
exec = "insert into bbs(Title,Data,UserName,Time)values('"+title+"','"+data+"','"+username+"','"+Now()+"')"
conn.execute exec
conn.close
set conn = nothing
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错误类型：
Microsoft VBScript 运行时错误 (0x800A000D)
类型不匹配: '[string: "insert into bbs(Titl"]'
/check_create.asp, 第 8 行
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如果我把Time,和Now()删去,正常运行,但怎样动态加入时间,我在ACCESS中的Time数据类型是'日期/时间'