You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Joshua Lewis, I want to change my existing reservation due to postpone of my interview.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: No issue, thank you for your service.

ASSISTANT: Thanks for reaching us, have a good day.