You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation as my plan to Yosemite Adventure got postponed, please help me out.

ASSISTANT: Sure, may I know your good name please?

USER: I am Joshua Robinson.

ASSISTANT: Thank you Joshua, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no flight on your name.

USER: Ok, no problem. Thank you for the response.

ASSISTANT: Thanks for choosing us. Have a good day.