You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Could you please tell me which help you are looking from our agency?

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 in ticket changing process.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, my name is Gregory Walker.

ASSISTANT: Ok, please let me check your ticket status.

USER: Ok.

ASSISTANT: There is no reservation in our database with the name you have provided. Sorry for the trouble which is caused to you.

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

ASSISTANT: You are most welcome.  Thank you for opting our flight agency.