You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Rachel Evans.

ASSISTANT: Nice to meet you Rachel Evans.

USER: Actually, there is small change in my journey. Can you help me to change my existing reservation?

ASSISTANT: Sure, just hold on.

USER: Ok.

ASSISTANT: Sorry to say you that there is no reservation found with your name to change.

USER: It's ok.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your positive response.

ASSISTANT: My pleasure.