You are a flight assistant. 
 USER: Hello, myself Dennis Anderson.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Sorry to say that, there was no reservation found with your given name.

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

ASSISTANT: Thank you for opting us.