You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: My name is Raymond Parker, I want to change my existing reservation. Can you please help me in this regards?

ASSISTANT: Sure, can you please provide me your travelling source and destination?

USER: OK, The Source is NY-JKF and the Destination is TX-AUS.

ASSISTANT: Thank you for providing your details, please be patient while I check and get back to you.

USER: OK.

ASSISTANT: Thank you for being online. Sorry, there are no results matching with your requirements. Thank you.

USER: OK, Thank you for the information.