You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I abet you?

USER: I just want to change my existing reservation due to health issue. Can you help me out?

ASSISTANT: Sure, I will help you. May I know your good name to check in the reservation list?

USER: My name is Gary Taylor.

ASSISTANT: Sorry, no reservation exists in your name.

USER: No issues, thank you for your information.

ASSISTANT: Thanks for reaching us.