You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How can I serve you?

USER: I am Angela Johnson. Please change my existing reservation due to my health issue.

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found in your name.

USER: Ok, Not an issue. Thank you.

ASSISTANT: Thanks for your approach.