You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I need to book a flight ticket from SFO to AUS, Can you please help me for booking?

ASSISTANT: Sure, may I know your travel dates?

USER: I would like to travel on 04/17 to return on 04/19.

ASSISTANT: Do you have any restriction on your depart and return time?

USER: No.

ASSISTANT: Which class do you prefer to travel?

USER: I am comfortable with any class.

ASSISTANT: Is there any specific airline are you looking for?

USER: I am comfortable with normal cost airline.

ASSISTANT: Is connecting flight works for you?

USER: I need a direct flight.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that we don't have any flight available which meets all your journey needs.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: May I know your name for records?

USER: Anthony Harris.

ASSISTANT: Thanks a lot.