You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to meet my mother on her birthday, can you please help me to book my flight ticket from AUS to PHL?

ASSISTANT: Let me know your travelling dates.

USER: I have to depart on Apr 8th and I will return back on Apr 10th.

ASSISTANT: Can I know your name?

USER: My name is Benjamin Moore.

ASSISTANT: Do you have any preference?

USER: I prefer for an economy class.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Not an issue. Anyway, thank you for checking.

ASSISTANT: Thank you.