You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Robert Lee.

ASSISTANT: Nice meeting you Lee. Welcome to flight booking agency.

USER: I would like to book a ticket  to Washington DC, can you please help me out in booking?

ASSISTANT: Sure, we are happy to help you. Can you please provide your preferable dates of travelling?

USER: I am travelling on these dates 10/03 and 10/05.

ASSISTANT: Ok, may I know your origin and destination airport codes for booking?

USER: I am flying from LGA to IAD.

ASSISTANT: Ok, 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 requested dates of travelling.

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

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