You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kimberly Moore.

ASSISTANT:  How can I assist you?

USER: I need to cancel my recent reservation due to postpone of my joining letter. Could you please help me in doing that?

ASSISTANT: Ok, please wait I will check the availability. sorry, no reservation was found on your name.

USER: No problem, thank you for your information.

ASSISTANT:  Thank you.