You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Thomas Moore. I want to change my existing reservation due to health issues, can you help me in change reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.