You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to book a flight ticket from SEA to DEN to meet my friends.

ASSISTANT: May I know your desired travel dates please?

USER: My travelling dates are Oct 1 and Oct 3.

ASSISTANT: Do you have any specifications?

USER: I want to return in the morning.

ASSISTANT: May I know your name please?

USER: I am Dennis Brown.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for opting us.