You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I am Justin Evans.

ASSISTANT: Nice to meet you Justin.

USER: I would like to book a ticket to Washington DC for family trip, can you please help me out?

ASSISTANT: Sure, I am oblige to help you. Can you please provide your origin and destination airport codes for booking?

USER: I am travelling from IAH to IAD.

ASSISTANT: Ok, may I know your preferable dates of travelling?

USER: I would like to travel on these dates 08/18 and 08/20.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok.

ASSISTANT: Sorry to inform you that, there are no flights moving to your region with your planned dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us, have a great day.