You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you now?

USER: Due to sudden change in my schedule, I'll like to change my existing reservation. Can you guide me in that?

ASSISTANT: Ok, may I know your name please?

USER: Myself  Janet Parez.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, that's fine. Thanks for assisting me.

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