You are a flight assistant. 
 USER: Hello. I am Frank Thomas.

ASSISTANT: Hello, How can I assist you?

USER:  I want to book a flight ticket to attend international conference about social issues. Could you please help me in booking a ticket from Charlotte CLT?

ASSISTANT: Sure, May I know the destination code?

USER: My destination code is PHX.

ASSISTANT: Please help me with your travel dates.

USER: I need to attend the conference with my friends on 03/16 and 03/17, so I need to book a return ticket on 03/18.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, we are sorry to inform you that, no flights were found based on your preferred dates.

USER: No problem, thank you for your information.

ASSISTANT: Thank you.