You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a flight ticket from SFO to CLT?

ASSISTANT: Please provide your travelling dates?

USER: My travel dates are May 14 and May 16.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Do you have any requirements?

USER: I prefer direct flight for this trip.

ASSISTANT: May I know your name?

USER: I am Larry Thompson.

ASSISTANT: Sorry currently there is no flight for your travelling dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.