You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in changing my reservation as my meeting got postponed?

ASSISTANT: Sure, I am here to help you with this. May I know your name please?

USER: I am Sandra Garcia.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Sandra, there is no reservation found as per your name to change it.

USER: Ok, no problem. Thank you.

ASSISTANT: You are welcome.