You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: My name is Dennis Garcia.

ASSISTANT: Ok.

USER: Owing to an emergency, I want to change my existing reservation.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name.

USER: No problem, thank you for your help.

ASSISTANT: Thank you for approaching us.