You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, How can I help you?

USER: I need to change my earlier reservation as I need to go for round trip. Please, help me in changing my existing reservation.

ASSISTANT: Sure, May I know your name?

USER: You can check the reservation with my name Thomas Perez.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, thank you for information.

ASSISTANT: Thank you for availing us.