You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I am Jack Mitchell. I want to meet my wife on her birthday, can you please help me to book my flight ticket from CLT to BOS?

ASSISTANT: Sure, please share me your trip dates.

USER: Sure, I have to depart on Dec 20th and I will return back on Dec 22nd.

ASSISTANT: Ok, do you need any specifications?

USER: I need direct flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us.