You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello.

USER: I am Patrick Turner.

ASSISTANT: How may I help you today?

USER: I want to book a flight ticket to attend Auto Show in San Francisco, CA - SFO. Can you book a flight ticket from Washington, DC - IAD?

ASSISTANT: Sure, when did you scheduled to travel & return?

USER: My travel dates are 05/16 - 05/18.

ASSISTANT: Please hold on.

USER: Sure.

ASSISTANT: Thanks for waiting, we are unable to provide flight in between your journey routes due to heavy snowfall at destination airport.

USER: Thanks for your helping hand.

ASSISTANT: Thank you for availing us.