A simple Playcount in text using AJAX?

I'm a noob on this. (sorry if I repeated a same kind of request)

I want to make a 'playcount hit counter' for myself to check on. (without interfering their play)

I believe AJAX can do that, is it?

Can AJAX send data into a text file, in certain URL?

When anyone reach a certain point(like a button click), it will add 1 to the text, like this.

And the numbers will keep adding up each click.

Can anyone show me how to do it simply, or any other ways? Thanks !