You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you aid me in booking a flight ticket from DEN to OAK?

ASSISTANT: Sure, can you please mention with your dates of journey?

USER: Sure, I would like to go on Mar 18th and return back on Mar 20th.

ASSISTANT: May I know your good name please?

USER: Myself Karen Wright.

ASSISTANT: Are you looking for any other help from my side please?

USER: Make sure the return time should be in the evening.

ASSISTANT: Please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Karen, there is no flight found as per your travelling details.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome.