When you click "Submit Donation" you will be redirected to the PayPal login.
IF YOU HAVE a PayPal account, login and complete your payment.
IF YOU DO NOT HAVE a PayPal account, select the button, on the bottom of the PayPal login form, labeled "Pay with Credit or Debit Card."
IF YOU WANT TO PAY BY CHECK, you need to use the "Check Payment" link in the email that was sent to you.