You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Christopher Williams.

ASSISTANT: What type of service do you need from our agency?

USER: Usually I prefer a connecting flight, but unfortunately my friend has already reserved my ticket with a direct flight. So, I want to change it. Can you please help me with this?

ASSISTANT: Sure, I am here to help you in changing the flight ticket details.

USER: Thank you.

ASSISTANT: Can you please allow me sometime? So that, I will check your ticket status.

USER: Sure, take your time.

ASSISTANT: Sorry to tell you, actually I have not found any active reservation with the name your have mentioned.

USER: Ok, not an issue.

ASSISTANT: Thank you for your positive response.

USER: Thank you for the information.

ASSISTANT: You are welcome. Thank you for choosing our agency.