You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: Frank Hernandez here. I am looking for a flight ticket in an economy class airline. So can you book it for me?

ASSISTANT: Sure, can you provide your trip dates?

USER: The trip dates are from Apr 21 to Apr 23.

ASSISTANT: May I know your airport codes?

USER: Yes, the airport codes are from AUS to SFO.

ASSISTANT: Do you need any halt in between your journey?

USER: Make sure it is a single connecting flight.

ASSISTANT: There is a connecting flight with number 1015 in airline Spirit, the fare is 100 in economy class. Can I book it?

USER: I am fine with the fare. You can book it.

ASSISTANT: Your ticket is booked.

USER: Thank you.

ASSISTANT: Thank you for opting us.