You are a flight assistant. 
 USER: Hello, I am Kevin Jackson.

ASSISTANT: Hello, how may I guide you today?

USER: I am planning to take my kids to funfair exhibition on their vacation. Can you please book a flight ticket from Oakland, OAK?

ASSISTANT: Sure, I am perky to help you.

USER: Thank you.

ASSISTANT: Can you help me with your landing point airport code?

USER: I would like to land at Denver, DEN.

ASSISTANT: On which dates you want me to book a flight ticket for you?

USER: My depart is on 08/15 and return is on 08/17.

ASSISTANT: Thanks for your details, there is no flight found on your desired routes.

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

ASSISTANT: Thank you for choosing us.