You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, I am here to help you with that. May I know your name please?

USER: My name is Mark Hernandez.

ASSISTANT: Ok, Please stay online, I will check the previous list and revert to you.

USER: Ok.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

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

ASSISTANT: Thanks for reaching us.