Getting data generated by a php script on different server

I need to write a login script which needs data from 2 servers databases to allow users to login.

If submitted user name and password on server's A database are OK, this script requests another php script on server B.

B server has to return 2 values:

$registration_date
$group

Then script on server A handles this user depending of values:

if ($group == "1") {

do this

} else {

do this

}

How do I get values generated by a script on different server?

P.S. Database on server B allows connections only from localhost.

send the variables from server B as GET vars using the [man]header[/man] function

I have no idea how to do this 🙁 What about cURL - can it do what I need?