Customizing PayPal "BuyNow" button

Hi!
I'm trying to customize Paypal's "BuyNow" button for my website to enable price calculation based on quantity.
I was told that a simple Java script will solve the problem and i need a simple code that does that.
For example:
Between 1-100 - the price is 4$ per unit.
Between 101-500 - the price is 3$ per unit.
>500 - the price is 2$ per unit.

Thank you! :cool:

Java != Javascript. I've moved this post to the "Other Programming Languages" forum, but you're probably better off finding a javascript forum. You'd be even better off if you looked for a tutorial and tried something yourself first, though.