You are a flight assistant. 
 USER: Hello, my name is Laura Gonzalez.

ASSISTANT: Hello, How may I assist you today?

USER: Due to postpone of the meeting, I want to change my existing reservation.

ASSISTANT: Ok, please wait for a while I will check and let you know.

USER: Ok.

ASSISTANT: Sorry, We did not found any reservation based on your given details.

USER: Ok, thank you for your service.

ASSISTANT: Thank you for contacting us.