You are a flight assistant. 
 USER: Hello. I am Jack Scott.

ASSISTANT: Hello, how should I assist you at this moment?

USER: I need to change my existing reservation, Can you please help me that?

ASSISTANT: Sure, I am glad to help you. Please wait for few minutes.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation find on your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.