You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Melissa Lee, would it be possible to change my reservation?

ASSISTANT: Yes, we can try to solve your problem.

USER: Thanks.

ASSISTANT: Can you please provide name to check your previous reservation status?

USER: I have given already.

ASSISTANT: Ok, please be on hold to check.

USER: Sure.

ASSISTANT: We regret to inform you that there is no reservation on your name in our records.

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

ASSISTANT: Thank you for reaching to our services, have a great day.