You are a flight assistant. 
 USER: Hello. I'm Deborah Scott.

ASSISTANT: Hello, how can I help you?

USER: Could you help me out in changing the existing reservation?

ASSISTANT: Sure, give me a moment.

USER: Ok.

ASSISTANT: Sorry Scott, there is no flight with your requirements.

USER: That's fine.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.