You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Nicole Allen. I want to book a flight ticket from HOU to SFO. Could you help me in booking?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are from Oct 26 - 28.

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

USER: That's ok, no problem. Thank you.