If you have the money already sitting in your PP account ?

The reason I ask this is I've noticed a number of websites that claim to take PP, ask for a credit card when paying, this get's a bit confusing and let me explain.

Not all countries who have what is called a "Debit card" act as a credit card at the same time, some are simply bank cards in other countries which do NOT act as an extension of CC.

Example I have: $100 sitting in pp, if I go through the checkout process on GW's website will I be able to pay that way or will they ask me for a CC to back up the payment, the reason I ask is I have no CC but am able to use PP by transferring funds from my bank account into PP itself.

Thanks for the help if anyone knows