Hello.
user
Hello. How can I aid you?
assistant
I am Timothy Roberts. I want to book a ticket  from IAD to LAS to meet my uncle, can you help me in booking?
user
Sure, may I know your journey dates?
assistant
I am departing on 08/10 and return on 08/12.
user
Sorry, there is no flight on your requested dates.
assistant
That's ok, thank you for your information.
user
Thank you for opting us.
assistant