Creating paypal checkout button with different prices?

I have a website giving services for money, i just want a button goes to a paypal checkout page with a price specified by me. There is no product or service name, just website name and price. But i couldn't find something like that. I have too many different prices, so i can't create buttons for every price. Is it possible to define price as a variable in my webpage, and send paypal this? I开发者_开发问答 use php.