求教密码验证问题

我设计的登陆系统要求同一个帐号登陆时候,如果密码输错三次,该帐号则被提示为非法用户,锁定帐号,我不会实现,请大家帮帮忙!谢谢!登陆处理页面如下
dim strSQL,strPress,i

strPress = Request.Form("zh")
strPress1 = Request.Form("mm")
i=0
if strPress<>"" then


Set conn = Server.CreateObject("ADODB.Connection")
strconn="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="&Server.MapPath("yonghu.mdb")
conn.open strconn

strSQL = "SELECT * FROM yonghu"
strSQL = strSQL & " WHERE id='"&Trim(strPress) & "'"
Set rs = Server.CreateObject("ADODB.Recordset")
rs.Open strSQL,conn

if rs.EOF then
response.write "<script>alert('没有此用户');window.navigate('main.htm');</script> "
else
if strPress1=rs("mima") then
response.write "<script>alert('登陆成功');window.navigate('main.htm');</script> "
else
response.write "<script>alert('密码错误');window.navigate('main.htm');</script> "
end if
rs.Close
conn.Close
end if
else
response.write "<script>alert('用户名不能为空');window.navigate('main.htm');</script> "

end if