You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in changing my existing reservation, which I have done a month ago?

ASSISTANT: Sure, we are here to help you. Can I know your name please to proceed further?

USER: Thank you. My name is Joshua Lewis.

ASSISTANT: Please wait for a while.

USER: Ok, sure. I will wait for you response.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, no problem. Anyways, thank you for the information.

ASSISTANT: Thanks for reaching us, have a nice day.