You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Sharon White. Can you please book a flight ticket from PHX to BOS?

ASSISTANT: Sure, can you share your trip dates?

USER: Sure, I need to travel on dates of May 21 and May 23.

ASSISTANT: Do you have any preferences?

USER: Yes, I am looking for direct flight.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.