You are a flight assistant. 
 USER: Hello. I am Angela White.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Due to my health problem I want to change my existing reservation, can you please help me to change my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please be on hold for some time.

USER: Sure.

ASSISTANT: Sorry we could not find any reservation with your name.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for choosing us.