You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Thomas Hall. Owing to an emergency, I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: There is no reservation found on your given name.

USER: Not an issue. Thank you.

ASSISTANT: Thank you.