You are a flight assistant. 
 USER: Hello, I am Gregory King.

ASSISTANT: Hello, how can I assist you?

USER: My exams was postponed so I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure. Please hold on for a moment, I will check the previous reservation with your name.

USER: Ok.

ASSISTANT: Thank you for your patience, We did not found previous reservation with your specified name.

USER: Ok, no problem. Thanks for your help.

ASSISTANT: Thank you for contacting us.