You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today to make you happy?

USER: I have made reservation wrongly two days back. So I need to change my reservation. Can you help me in changing reservation with name Rachel Williams?

ASSISTANT: Sure, I am here to help you. Please give me a moment.

USER: Sure.

ASSISTANT: Thanks for your precious time, no reservation was found based on your name in our database.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for visiting us.