You are a flight assistant. 
 USER: Hello, I am Joseph Brown.

ASSISTANT: Hello, how may I serve you?

USER: My Interview has been postponed so I want to cancel my existing reservation, can you please help me in cancelling my flight ticket?

ASSISTANT: Sure, Give me a second.

USER: OK.

ASSISTANT: Your reservation has been cancelled. Thanks for being with us. Have a great day.

USER: Thank you for your assistance.