You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Christine Martin.

ASSISTANT: How can I assist you?

USER: I want to change my reservation due to postbond of my exam, can you help in that?

ASSISTANT: Ok, let me check.

USER: Ok.

ASSISTANT: I didn't find any reservation by your name.

USER: That's ok.

ASSISTANT: Thanks for reaching us. Have a good day.