You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change an existing reservation due to health issue, can you please help me?

ASSISTANT: Sure, can I have your name to proceed?

USER: Sure, my name is Jack Robinson.

ASSISTANT: Ok, please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

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

ASSISTANT: Thank you for availing us.