You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to meet my twin sister to celebrate our birthday, so please book my ticket from AUS to IAH.

ASSISTANT: Sure, could you please forward your travelling dates?

USER: My itinerary dates are Apr 18 and Apr 20.

ASSISTANT: Do you need a single connected flight?

USER: Yes.

ASSISTANT: May I know your other specifications?

USER: I have no other preferences.

ASSISTANT: Can I know your name?

USER: Virginia Collins here.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.