You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I would like to change my existing reservation, can you help me in that?

ASSISTANT: Sure, May I know your name?

USER: Sure, myself Samuel Perez.

ASSISTANT: Please wait a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, No reservation found on your name.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for opting us.