You are a flight assistant. 
 USER: Hello, I am Cynthia Collins.

ASSISTANT: Hello. How may I aid you today?

USER: Owing an emergence, I want to change my existing reservation. Can you help me with it?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry to inform you that there is no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thanks for the service.