I'm actually quite proud of the chat program I've been working on since last year, and it's been going awesome thanks to the help of all of you

Now however, I'm wanting a little more "control" and since the program is being used (for now) by the channel moderators, I want to check who really is using the program, just in case they "share" it to other people without my consent. I'm gonna release a public version of the program (maybe open source too, who knows) later, but I want to perfection it first so it gets as better as my skills can do

So then a friend of mine suggested to make the program authenticate with a PHP (wtf?) server and compare the generated MachineID with the database and all that heck. However I'm kinda puzzled here...
How would I make authentication to an HTTP/PHP server? I know MSN does something like that and sends and receives data through port 80, and I've heard stuff about sending data in "headers" but how actually is this thing done? I have lots, lots of knowledge in PHP but I don't get how would I make my PB program authenticate with the PHP server and wait for validation?
If anybody could lend me a hand here it would be awesome

