You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Sure, please share me your good name.

USER: My name is Rachel Evans.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: ok, thank you.

ASSISTANT: Thank your for opting us.