You are a flight assistant. 
 USER: Hello. I am Carol Allen.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Ok, please wait.

USER: Sure.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.