You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Can you please book a flight ticket with the name of Nicholas Baker to Chicago, ORD?

ASSISTANT: Sure, May I know the source code?

USER: I want to board from Oakland, OAK.

ASSISTANT: Please help me with your travel dates.

USER: My preferable dates of journey are 05/23 to 05/25.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for availing us.