asp新手请asp高手把把关！

项目的需要，扭捏出下面这点asp代码用于用户注册，高手给看看怎样进行必要的错误处理，关键资源（数据库表）怎样进行并发保护？比如多个个用户用同一个用户名在同时注册，该怎样处理？
谢谢！

<%
'用户注册

dim name, password, email, company
name = request.form("name")
password = request.form("password")
email = request.form("email")
company = request.form("company")
dim db, conn, connstr, sql, rs
db = "data/database.mdb"
set conn = server.createobject("ADODB.connection")
connstr = "provider=microsoft.JET.OLEDB.4.0;data source=" & server.mappath(db)
conn.open connstr
sql = "select top 1 * from [Users] where Name = '" & trim(name) & "'"
set rs = server.createobject("ADODB.recordset")
rs.open sql, conn, 3, 2
if rs.RecordCount = 1 then
response.write("FAILED")
else
rs.addnew
rs("name") = name
rs("password") = password
rs("email") = email
rs("company") = company
'rs("logincount") = 0
rs.update
rs.close
response.write("SUCCESSFUL")
end if

set rs = nothing
set comm = nothing
%>