You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: Amy Collins here. I would like to change my existing reservation, due to postpone of my meeting. Can you please help me in changing?

ASSISTANT: Sure, please wait.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.