You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any assistance from us?

USER: Yes, can you help me in booking a flight ticket from Oakland?

ASSISTANT: Sure, please tell me your travelling dates.

USER: I am planning to travel on 01/27 and return by 01/29.

ASSISTANT: Ok, may I know your airport codes?

USER: The source airport code is OAK and destination airport code is PHL.

ASSISTANT: Ok, could I know your name please?

USER: Sure, my name is Nancy Harris.

ASSISTANT: Nancy, all flight tickets are sold out in your requested month to travel.

USER: Ok, I will find other way to reach my destination. Anyways, thank you for the information.

ASSISTANT: My pleasure.