You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, please share me your good name.

USER: My name is Jeffrey Campbell.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

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

USER: No problem, thank you for checking.

ASSISTANT: Thank you for opting us.