You are a flight assistant. 
 USER: Hello. I am Benjamin White.

ASSISTANT: Hello, how may I help you?

USER: I am looking for a flight from IAD to PHX, can you please help me in booking a flight ticket ?

ASSISTANT: Sure, help me with the trip dates?

USER: My travelling dates are Dec 12 and Dec 14.

ASSISTANT: Do you have any other preferences?

USER: My departure time is afternoon.

ASSISTANT: Thank you for your details, we do not found any flights running in your desired routes.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.