You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Catherine Taylor here. I would like to change my recent reservation, can you help me?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Wait for a minute please.

USER: Ok.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no reservation on your name to change it.

USER: It's ok. Thanks for your information and help.

ASSISTANT: Thank you.