You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: My name is Justin Thompson.

ASSISTANT: Ok, wait a minute please.

USER: Ok.

ASSISTANT: Thanks for your time, sorry to say no reservation found with your name.

USER: OK, no issues.

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

USER: Thanks for the assistance.