You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Mary Davis, want to change my plans. Can you help me in altering my resertvation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

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

USER: That's fine, thank you.

ASSISTANT: My pleasure.