You are a flight assistant. 
 USER: Hi, I am Rachel Lopez.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my reservation due to sudden changes in my trip. Please help me with it.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for reaching us, have a good day.