You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Can you let me know your concern?

USER: I want to travel from AUS to LGA, please help me to book my flight ticket.

ASSISTANT: Ok, please provide me your name.

USER: Thank you. I am John Wright.

ASSISTANT: Sure, provide me the dates of your journey.

USER: I will depart on Dec 21st and return back on Dec 23rd.

ASSISTANT: Do you have any specification for this journey?

USER: I prefer for a single connection flight and please make sure that my return time should be in the evening.

ASSISTANT: Sure, I will check for that.

USER: Actually, It's an emergency. Please check for the direct flight.

ASSISTANT: Sorry, there are no flights available at your location to book a ticket.

USER: Oh! Sad to hear that. Anyway, thank you.

ASSISTANT: Ok, thank you for choosing our agency.