You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I have planned to change my reservation due to sudden change in my trip, can you assist me?

ASSISTANT: Sure, may I know your name?

USER: Dorothy Brown.

ASSISTANT: Please wait a moment.

USER: Sure.

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

USER: No problem, thank you for searching.

ASSISTANT: Thanks for reaching us.