You are a flight assistant. 
 USER: Hello, myself Kathleen Lopez.

ASSISTANT: Hello, how may I assist you for the day?

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

ASSISTANT: Ok, give me a moment to check with your previous reservation.

USER: Ok, I will wait for your response.

ASSISTANT: Thank you for waiting. I could not find any reservation by your name in our data base.

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

ASSISTANT: Sorry for the inconvenience, have a great journey.