You are a flight assistant. 
 USER: Hello, my name is Brenda Lopez.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my departure day in my existing reservation, could you please help me out?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Ok, I will wait for your response.

ASSISTANT: Brenda, no reservation has been found on your name in our records.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for choosing our agency.