You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My name is Anna Jackson,want to book a ticket.

ASSISTANT: Sure Anna, can you please provide the city names?

USER: I want to travel from PHL to AUS.

ASSISTANT: Ok, can you please provide the travel dates?

USER: My travelling dates will be 05/15 and 05/17.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no flights found under your requirements.

USER: Oh!it's OK.

ASSISTANT: Thank you, have a nice day!.