You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I aid you today?

USER: I am Scott Anderson want to change my existing reservation due to postpone of my meeting. Can you help me in changing my reservation?

ASSISTANT: Ok, Wait a minute.

USER: Ok.

ASSISTANT: Sorry to tell that there is no flight found on your journey details.

USER: Thank you for your response.

ASSISTANT: Thank you for choosing us.