You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my previous travel dates, which is done recently. Can you please help me out?

ASSISTANT: Sure, may I know your name please?

USER: Sure, myself John Campbell.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no active reservation found with your name in our records.

USER: Not an issue with this one, anyway thank you for the information.

ASSISTANT: Most welcome.