You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please assist me with altering my previous booking and changing my journey airport codes?

ASSISTANT: Sure, may I know your name?

USER: My ticket was previously booked by the name of Brandon Adams.

ASSISTANT: Please wait a moment, let me check with the details.

USER: I will be waiting for your response.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: Oh! That's very sad news for me. Anyways, thank you for checking.

ASSISTANT: Thank you for reaching our service.

USER: You are welcome.