You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Christine Perez. I want to change an existing reservation, due to my health issues. Could you help me in changing a reservation?

ASSISTANT: Sure, I will help you. Please wait.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Not an issue. Thank you for your service.

ASSISTANT: Thank you. Have a great day.