'The flowers were beautiful! Thank you!'
'Thank you for prompt delivery'
'Everything looked very nice, from the flowers, the basket, & the hunter's orange ribbon. The woman who took my order was very pleasant & friendly. The only thing is that the flowers online were white & the one sent were yellow.'
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.