You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Robert Green.

ASSISTANT: How may I aid you today?

USER: I am planning to start a new gym at Dallas, help me in booking my flight ticket from San Francisco CA-SFO.

ASSISTANT: Sure, may I know your destination code?

USER: My landing airport code is TX-DFW.

ASSISTANT: When are you willing to travel?

USER: I would be start on 01/28, my return date is on 01/30.

ASSISTANT: Do you have any price limit?

USER: I need a connection.

ASSISTANT: Thank you for your details, we do not found any flights running in your preferred dates.

USER: Its ok, thank you.

ASSISTANT: Thank you for opting us.