You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Betty Thomas.

ASSISTANT: How may I guide you?

USER: I want to book a ticket from AUS to SFO to attend friend's birthday party, can you help me in booking?

ASSISTANT: Sure, I will help you. May I know your travel dates please?

USER: I am departing on 09/15 and return on 09/17.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Betty, no flights has been found on your journey dates.

USER: That's fine, thank you for your information.

ASSISTANT: Thank you for choosing our services.