'I happened to see the flowers at the funeral and they were just as ordered and expected. Thank you for your help!'
'The flowers for our friend's celebration of life memorial service were spectacularly beautiful. She would have enjoyed them so much. Thank you!'
'Dear sir/madam, We have received the flowers. Thank you! The arrangement was large, fresh and of colors we ordered. Even if we would prefer calla lilies, as we ordered, we are still satisfied, the replacement were beautiful orchids. The only one note would be from us: the message was on a plain paper and not printed. We expected it to be on a card. Other then that we are happy with the purchase.'
You won't be able to dismiss this by usual means (escape or click button), but you can close it programatically based on user choices or actions.