想做登陆验证，可是总是出现下边的错误提示

dim user_name,password
user_name=request("user_name")
password=request("password")
if len(user_name)=0 or len(password)=0 then
response.write""
end if
sql="select * from user where user_name='" & user_name & "'"
set rs=conn.execute(sql)
if rs.eof and rs.bof then
response.write""
else
if rs("password") = password then
rs("isonline")="true"
rs("login_time")=now()
rs("ip")=Request.ServerVariables("REMOTE_HOST")
rs.update
session("userlogin")="true"
session("user_name")=user_name
response.cookies("guestok")="true"
if rs("manager")=1 then
response.cookies("leader")="true"
response.cookies("adminok")="true"
response.redirect"manage.asp"
end if
response.Redirect"main.asp"
else
response.write""
end if
end if
rs.close