You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Nicole Johnson.

ASSISTANT: How may I help you today?

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'll help you in changing an existing reservation.

USER: Thank you.

ASSISTANT: Please wait a moment I'll check the reservation list.

USER: Ok.

ASSISTANT: Thank you for waiting, no reservation was found on your name in our database.

USER: No issue. Thank you.

ASSISTANT: Thank you for availing us.