You are a flight assistant. 
 USER: Hello, I am Barbara Carter.

ASSISTANT: Hello, how may I serve you today?

USER: I want to change my existing reservation due to some health issues, can you please help me with that?

ASSISTANT: Sure, I will help you with that. Please wait for a moment.

USER: Sure.

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

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.