You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your good name please?

USER: My name is Matthew Thomas.

ASSISTANT: How may I assist you Matthew Thomas?

USER: I want to change my existing reservation due to health issues.

ASSISTANT: Ok, please hold on a while. I will check with your name and change it accordingly.

USER: Ok.

ASSISTANT: Thanks for being hold, we did not find any reservation done on your name.

USER: No problem, thanks for your good service.

ASSISTANT: It's our pleasure to serve you, we look forward to hear from you. Thank you.