You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gregory Jackson.

ASSISTANT: How may I aid you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Ok.

ASSISTANT: Jackson, no reservation has been found on your name in our records.

USER: No issue. Thank you.

ASSISTANT: Thank you for choosing our services.