You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I am Dorothy Walker, want to travel from IAD to AUS. Please help me in ticket booking.

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: My travelling dates are from 01/30 to 02/01.

ASSISTANT: Please wait for a minute.

USER: Ok.

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

USER: It's ok, thank you.

ASSISTANT: Thank you for contacting us.