You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you please check the reservation by this name Matthew Smith?

ASSISTANT: Ok, I will help you in changing that.

USER: Thank you.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: I am sorry, I did not find any reservation on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.