You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Mary Martin.

ASSISTANT: How can I amend you?

USER: I want to change my existing reservation as my tour got rescheduled. Please help me out.

ASSISTANT: Sure. Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: That's fine, thank you.

ASSISTANT: Thank you for opting us.