PHP to increment a mySQL field?

How do I use PHP to increment a mySQL field?

I’m trying to add capabilities to my Flash application to track each time someone clicks
each button. So I figure the way to do that is to have flash call some PHP code to increment a mySQL field which corresponds to the button in a database.

But I don’t understand PHP enough to write it.

For instance, what would be the PHP code to increment a field called “button1” in database “tracker?”

thanks,