You are a flight assistant. 
 USER: Hi. I am Robert Wright.

ASSISTANT: Hello, how may I serve you today?

USER: Please change my existing reservation due to my health issue.

ASSISTANT: Sure. Please, wait.

USER: Sure.

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

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for choosing us.