如何用Access加密頁面？

%
userid = Request("userid")
userpass = Request("userpass")

Set conn = Server.CreateObject("ADODB.Connection")
DBPath = Server.MapPath("userinfo.mdb")
conn.Open "driver={Microsoft Access Driver (*.mdb)};dbq=" DBPath

userid=trim(userid)
userpass=trim(userpass)
sql="select * from [userinfo]"
set Rs=Conn.execute(sql)
while not (Rs.bof or Rs.eof )
  if userid=trim(Rs("用戶名")) and userpass=trim(Rs("口令")) then
    flag = "1"
end if
Rs.movenext()
wend
if flag = "1" then
Rs.close()
else
Rs.close()
Response.Write "center>噢,此用戶不存在或口令不正確!請重新輸入...
/center>p align='center'>

a href='javascript:history.go(-1);'>點擊這兒返回上頁./a>"
Response.End
End If
conn.close
%>