You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Nicholas walker here. I want you to make my flight reservation from OAK to LAX. Can you please help me?

ASSISTANT: On what dates you are willing to travel?

USER: Sure, I will depart on 12/03 and also please book my return ticket on 12/05.

ASSISTANT: Sorry, there is no flight for you on your route to book your ticket.

USER: Sad to hear that. Anyway, thank you.

ASSISTANT: Welcome Nicholas Walker.