You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER:  I am Rachel Garcia want to change my reservation due to prepone of my meeting. Can you help me with it?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: Thank you for your response.

ASSISTANT: Thank you.