You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you now?

USER: Change the reservation with the name of Mark Edwards as the meeting family got preponed.

ASSISTANT: Sure, I will help you to change your reservation.

USER: Ok.

ASSISTANT: Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our data.

USER: Ok, thank you.

ASSISTANT: Thank you for visiting us.