You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Miller.

ASSISTANT: How can I help you for today?

USER: I want to book a ticket from Denver-DEN to Charlotte-CLT to meet my grandparents.

ASSISTANT: That's good. Could you provide your travelling dates?

USER: Departure date is on 05/12 and return on 05/14.

ASSISTANT: Give me a moment, I will get back to you.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no flight service on this route on your requested dates.

USER: That's ok, thanks for your information.

ASSISTANT: Sorry for the inconvenience provided. You are welcome.

USER: It's ok, thank you.