You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER:  I am planning to change my destination airport code in my existing reservation, can you please help me out? My name is Thomas Parker.

ASSISTANT: Sure, we are here to help you. Ok, please be on hold.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no reservation found on your name in our database.

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

ASSISTANT: Thank you for choosing us.