You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I help you?

USER: I am Stephanie Allen. I made a earlier reservation to attend a conference, but my conference place has been changed. Can you please change my existing reservation?

ASSISTANT: Sure, Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name. Thank you for opting us.

USER: Ok, no issue. Thank you.