You are a flight assistant. 
 USER: Hello, I am Kimberley Roberts.

ASSISTANT: Hello, How can I help you out?

USER: I want to change my existing reservation as journey dates are rescheduled due to postpone of meeting. Can you help me in changing my reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, but no reservation existed with your name.

USER: Ok, no issues.

ASSISTANT: Thank You for choosing us.

USER: Thank you for quick response.