You can enter a URL here for a web page
that users will be taken to when they
complete a donation.  This is useful for
taking the user back to your site and
displaying a "Thank You".  NOTE: PayPal
will use this link for cancelled payments
as well. If you use the feature, also
create a second web page with appropriate
text for a cancelled payment.  TIP: Use
NukeWrap to bring your users back into the
Nuke site.