You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I intend to change my existing reservation as my plan to go on a vacation got cancelled. Can you help me with it?

ASSISTANT: Sure. Can I know your name?

USER: Joshua Davis is my name.

ASSISTANT: Give me a minute.

USER: Ok.

ASSISTANT: Thanks for your time. We didnt found any reservation by this name.

USER: Ok, thank you for the response.

ASSISTANT: Thank you for choosing us.