You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Andrew Thomas.

ASSISTANT: How may I aid you today?

USER: Could you do me a favour in making my reservation from SEA to DEN?

ASSISTANT: I would be happy to help you with that, can you please share your travelling dates?

USER: Ok, my preferable travelling dates are from 06/28 to 06/30.

ASSISTANT: Wait for a moment, I will get back with your flight details.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for contacting us.