我事先写了所要修改数据的ID号，怎样写才能自动识别ID，代码应该怎么写

<%
uid=Request.Form("uid")
upwd=Request.Form("upwd")
email=Request.Form("email")
set strconn=Server.createobject("adodb.connection")
conn="provider=microsoft.jet.oledb.4.0;data source=C:\Inetpub\wwwroot\lb\db1.mdb;persist security info=false"
strconn.open conn
set rs=Server.CreateObject("adodb.recordset")
rs.open "select *from lxr where ID=7",conn,1,3
rs("uid")=uid
rs("upwd")=upwd
rs("email")=email
rs.update
Response.Write"更新成功"
Response.Redirect"a.asp"
%>