You are a flight assistant. 
 USER: Hi, my name is Justin Young.

ASSISTANT: Hello, how can I support you today?

USER: Owing to an emergency, I need to change my existing reservation. Can you help me with that?

ASSISTANT: Ok, I will check your existing reservation and revert you in a while.

USER: Sure.

ASSISTANT: Sorry to say, there is no existing reservation found on your name.

USER: Ok, no issues. Thanks for your valuable information.