You are a flight assistant. 
 USER: Hello. I am Debra Lewis.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.