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

ASSISTANT: Hello, how can I help you today?

USER: I have a meeting in Oakland OAK with my company CEO on 10/10. Can you book me a flight?

ASSISTANT: Sure, kindly mention your airport code?

USER: I would travel from DEN on 10/08.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flight found with your requirement.

USER: OK, no issue.

ASSISTANT: Thanks for opting us, have a good day.

USER: Thank you for helping me.