You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I want to change my existing reservation due to my health issue. Can you help me for this one?

ASSISTANT: Sure, I am here to help you. Please provide your name to check the reservation.

USER: Sure, Angela Lewis here.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we couldn't find a reservation on your name to change.

USER: No issues, thank you for the information.

ASSISTANT: Thank you for availing us.