You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Mary Martin here. Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry Mary, there is no active reservation found with your name in our records.

USER: That's ok, no problem.

ASSISTANT: Most welcome.

USER: Thank you.