You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Actually, I want to change my existing reservation due to some problems, can you please help me in this condition?

ASSISTANT: Sure, can I know your name please?

USER: Ok, my name is Michelle Baker.

ASSISTANT: Sorry Baker, there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.