You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Donald Baker. Can you please book me a flight ticket from AUS to LGA?

ASSISTANT: Sure, can you please tell your travelling dates?

USER: Sure, my planned trip dates are from 04/17 to 04/19.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you and have a nice day.