You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

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

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Anthony Gonzalez here.

ASSISTANT: Ok, wait for a minute.

USER: Sure, take your own time.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for reaching us.