You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Betty Perez.

ASSISTANT: How can I assist you?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Sure.

ASSISTANT: Wait for a moment.

USER: Ok.

ASSISTANT: Sorry, I did not find your reservation details in our database.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you fro connecting us.