You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, can you please tell me how can I aid you?

USER: Please book a ticket to Ausitn, TX-AUS from San Fracisco, CA-SFO, for business trip.

ASSISTANT: Ok, sure I  will book your flight ticket. Mean while can you please tell me your travel dates?

USER: 04/11 is departure date and return date is 04/13.

ASSISTANT: May I know your name?

USER: I am Jonathan Anderson.

ASSISTANT: Sorry, I did not find any flights on your route with in my agency flights.

USER: Thanks.

ASSISTANT:  Thank you for making us to serve you today.