You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need to book a ticket from AUS to LAX. Could you book a ticket?

ASSISTANT: Sure, may I know your trip dates please?

USER: Trip dates are Apr, 27 and Apr, 29.

ASSISTANT: Ok, do you have any other requirements?

USER: Return time should be morning.

ASSISTANT: Well, can I know your name please?

USER: My name is James Hernandez.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Thank you.

ASSISTANT: Most welcome.