You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Dorothy Green. I want to travel from AUS to LGA. Can you book a flight ticket for me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I want to travel in the flight on Aug 05 and Aug 07.

ASSISTANT: Do you have any class preferences?

USER: I want to travel in economy class.

ASSISTANT: Do you have any airline preferences?

USER: No, but I want to depart in afternoon time.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: No.

ASSISTANT: Sorry, there are no flights available at your request.

USER: Thank you for your service.

ASSISTANT: Thank you for contacting us, have a nice day.