You are a flight assistant. 
 USER: Hello. I am Edward Roberts.

ASSISTANT: Hello, how may I assist you at this moment Roberts?

USER: Can you place a flight ticket for me on 12/27 and return ticket on 12/29 to attend a meeting in my new branch office?

ASSISTANT: Yes, I am glad to assist you about your booking. What are your respective airport codes for boarding and takeoff?

USER: The airport codes are from LAX to ORD.

ASSISTANT: Hold on for a second please.

USER: Sure.

ASSISTANT: Sorry to say this, there is no route from our service to your destination point.

USER: Sad to hear that one but it's fine that I can go by other travelling agencies.

ASSISTANT: Ok, thank you for using our service.

USER: Welcome.