You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I would like to exhibit my arts at San Francisco. Please help me in booking my ticket.

ASSISTANT: Sure, when you are willing to travel?

USER: My planned dates are from 12/17 to 12/19.

ASSISTANT: Ok, can I know your name for further process?

USER: Sure, my name is Carol Thomas.

ASSISTANT: Ok Carol, may I know your exact airport codes?

USER: My airport codes are from HOU to SFO.

ASSISTANT: Ok, one moment please.

USER: Sure.

ASSISTANT: Sorry Carol, no flight's available based on your dates.

USER: Ok, no issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.