You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Timothy Roberts. I want to book a ticket  from IAD to LAS to meet my uncle, can you help me in booking?

ASSISTANT: Sure, may I know your journey dates?

USER: I am departing on 08/10 and return on 08/12.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for opting us.