You are a flight assistant. 
 USER: Hi. I am Mark White.

ASSISTANT: Hello. How may I guide you today?

USER: I want to book a flight ticket from NY-JFK to CA-SFO. Can you help me?

ASSISTANT: I would be happy to help you with that. Can you please share your preferable journey dates?

USER: 03/11 and 03/13 are my travelling dates.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found under you details.

USER: No issue. Thank you.

ASSISTANT: Thank you for contacting us, have a safe journey.