You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

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

ASSISTANT: Sure, I am here to assist you.

USER: Thank you.

ASSISTANT: May I know your name, to check your reservation status?

USER: Sure, myself Ruth Davis.

ASSISTANT: Thanks for the details, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry for the inconvenience, there is no active reservation on your name to change it.

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

ASSISTANT: Thanks for approaching us.