You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: Due to an emergency, I want to change my existing reservation. Can you do for me?

ASSISTANT: Sure, we will help you to change your existing reservation. Please wait for a while. To proceed further, may I know your name?

USER: Samuel Hall here. Sure.

ASSISTANT: There was no reservation found on the name of Samuel Hall.

USER: No issue. Thank you.

ASSISTANT: Thank you for reaching us.