You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I address you?

USER: Please, change my existing reservation as meeting got postponed.

ASSISTANT: Sure, can you please provide your name?

USER: Reservation is done with my name Samuel Perez.

ASSISTANT: Please wait for a minute, I will get back to you.

USER: Sure.

ASSISTANT: I am sorry to inform that there is no reservation found with your name.

USER: Ok, thank you for information.

ASSISTANT: Thanks for reaching us.