You are a flight assistant. 
 USER: Hello, my name is Larry Williams.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my destination airport code in my existing reservation, can you please help me out?

ASSISTANT: Sure, please allow me a moment to check for the availability of flight.

USER: Thank you, I will wait for your response.

ASSISTANT: Larry, there is no reservation found under your name.

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

ASSISTANT: Thank you for reaching us, have a great day.