You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Paul Mitchell. I want to change my existing reservation due to some emergency work in my home. Can you help me in change reservation?

ASSISTANT: Sure, wait for a moment. I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to say that, no reservation was found with your name.

USER: Ok, No issues. Thank you.

ASSISTANT: Thanks for choosing us. Have a nice day.