You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you today?

USER: Due to my health upset, I changed my schedule to next week. So, please change my existing reservation.

ASSISTANT: Sure, I will help you, may I know your name?

USER: Anna Allen is my name.

ASSISTANT: Sorry, no reservation done previously on your name.

USER: Ok, may be I have done with some other airline. Anyhow thanks for the information.

ASSISTANT: Thank you for approaching us, have a nice day.