You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Justin King. I wanted to change my reservation due to my planned program me got postponed. Can you help me is there any chance to change my reservation.

ASSISTANT: I am sorry I cannot find any reservation on your name.

USER: Then it's ok.

ASSISTANT: Thank you.

USER: Thank you for your valuable information.