You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Emma Mitchell.

ASSISTANT: How may I assist you today?

USER: I want to change my destination airport code in my existing reservation, could you mind help me in changing?

ASSISTANT: Sure, I am happy to help you.

USER: Nice to hear that.

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

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

ASSISTANT: Thank you for approaching us.