How to add Alertpay Donate Button

Many times I have read about a alertpay donate button. you know those button where the  users can donate small amount 2 the site. But finding 1 is really tough. Paypal™ has a donate button, but you can donate only if you have a Paypal™ account. But everyone doesn't has a Paypal™ account.
So the other option is 2 allow people to use their credit-cards to donate. But to enable this feature you have to pay an excess of 20-25%. Now that is a real rip off.