You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I have to change my flight ticket booking done in the last week that I am unable to travel, can you please help me in that one?

ASSISTANT: Sure, please give me a moment. Please mention your name for checking the reservation.

USER: Sure, my name is Mark Phillips.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: Ok, no problem with that one. Thank you for your help.

ASSISTANT: Welcome, have a great day.