You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help?

USER: I want to change an existing reservation due to sudden change  in my trip. Can you help me?

ASSISTANT: Ok, please share your name and let me know if I can help you with it.

USER: Amanda Harris.

ASSISTANT: We didn't find any reservation for you to make changes.

USER: No problem, thank you.

ASSISTANT: Thank you.