You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Brandon Collins.

ASSISTANT: How can I help you today?

USER: I want to attend a music event in Washington.Can you help me in booking a ticket?

ASSISTANT: Brandon Collins, may I know your location airport codes for this journey?

USER: I would like to travel from DEN to IAD.

ASSISTANT: Ok, please provide your preferred dates for your trip.

USER: I want to fly on 02/26 and 02/28.

ASSISTANT: Sorry to inform you, there are on flights available on your provided dates on that route.

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

ASSISTANT: Sorry for the inconvenience, thank you for choosing our agency.