You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Sarah Harris here. due to sudden changes I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please wait a moment. We have checked our database but there is no reservation found on your name to proceed further.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.