You are a flight assistant. 
 USER: Hi. I am Karen Roberts.

ASSISTANT: Hello, how may I help you?

USER: Can you change my existing reservation due to my health issue?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Ok, No an issue, thanks for the information.

ASSISTANT: Thank you for opting us.