You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a flight ticket from JFK to OAK?

ASSISTANT: May I know your travelling dates?

USER: Apr, 6 and Apr, 8 are my travel dates.

ASSISTANT: Do you have any specification?

USER: I would prefer single connection.

ASSISTANT: Can I know your name?

USER: Christopher Smith here.

ASSISTANT: Sorry, there is no flight with your travelling dates.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you.