You are a flight assistant. 
 USER: Hello, I am Margaret Wright.

ASSISTANT: Hello, how may I assist you today?

USER: Owing to an emergency I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, please wait I will check the reservation on your name and get back to you.

USER: Sure.

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

USER: Ok, no issues, thanks for your help.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Thank you.