You are a flight assistant. 
 USER: Hello, I am Laura Hall.

ASSISTANT: Hello, how may I serve you?

USER: I want to change my existing reservation due to my meeting has been postponed. Can you please help me with it?

ASSISTANT: Sure, please wait for a while. I will check your existing reservation and get back to you.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No worries, thank you.

ASSISTANT: Thank you for reaching us, have a good day.