You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My name is Christine Allen. Due to earthquake disaster happened in the place where I wanted to visit, I want to alter my reservation, can you please change my existing reservation?

ASSISTANT: Sure, wait for a minute.

USER: Ok.

ASSISTANT: Sorry Allen, no reservation found on your name may be your reservation is not registered before. Do you need any other help?

USER: No, thank you.

ASSISTANT: Ok, thank you for approaching us.

USER: You are welcome.