You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Can you help me to book a flight ticket from IAD to DEN?

ASSISTANT: Sure, We are here to help you. Can I know your travelling dates?

USER: My trip dates are 11 to 13 of May.

ASSISTANT: Do you need any break?

USER: I am ok with any connection limit.

ASSISTANT: May I know your name?

USER: I am Stephen Hill.

ASSISTANT: Is there any other specifications?

USER: I would like to travel in business class.

ASSISTANT: Please be on hold for sometime, as I can check a flight for your journey with the best airlines.

USER: Sure.

ASSISTANT: We are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for reaching us.