You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I planned to meet my friend in ATL, can you please help me to book a flight ticket from IAD?

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

USER: I prefer to travel on May 18 and May 20.

ASSISTANT: Do you need any break?

USER: I need a direct flight.

ASSISTANT: May I know your name?

USER: I am Gregory Nelson.

ASSISTANT: Is there any other specifications?

USER: No.

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

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.