You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to change my reservation?

ASSISTANT: Yes, I am here to help you. May I know your name please?

USER: My name is William Turner.

ASSISTANT: Ok, please stand by.

USER: Sure.

ASSISTANT: Thank you for your time, sorry we didn't find any reservation on your name.

USER: Ok, not a problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you.