You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Actually, I want to amend my existing reservation due to health issues.Can you please help me out?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: Please mention your name to check your previous reservation.

USER: Sure, my name is James Taylor here.

ASSISTANT: Please allow me a moment.

USER: Sure, I will wait.

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

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Welcome, have a nice day.

USER: Thank you.