You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Brian Lee.

ASSISTANT: Yes, Lee.

USER: I am planning to travel on 06/29. Help in finding a flight?

ASSISTANT: Sure, I will deal in booking the flight ticket. Can I know your location airport codes please?

USER: My travel airport codes are ORD to OAK.

ASSISTANT: Ok, when you want to return back to ORD?

USER: I want  to back on 07/01.

ASSISTANT: Sorry Lee, no flights are there in your route. Do you have any other planned trip details?

USER: No, I'm ok with this. Thank you for helping me.

ASSISTANT: Ok, thank you for reaching us.