You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

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

ASSISTANT: Sure, please share me your good name.

USER: Sure, my name is David Martinez.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry to say that, there is no active reservation found on your good name.

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

ASSISTANT: Thank you for opting us.