You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I'm Laura Evans, and I want to change my existing reservation, can you please help me?

ASSISTANT: Sure Laura, please wait a moment to check.

USER: Ok.

ASSISTANT: Sorry Laura, unfortunately there is no reservation found under your name.

USER: No problem. Thank you, for your information.

ASSISTANT: Thank you for choosing our service, have a good day.