You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

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 with your concern.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Robert Gonzalez here.

ASSISTANT: Please hold on a moment.

USER: Ok.

ASSISTANT: Robert Gonzalez, no reservation has been found on your name in our database.

USER: No issue, Thank you for the information.

ASSISTANT: Thank you for approaching us.