You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Christopher Mitchell, can you help me to change the reservation I had done a week ago?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Ok, thank you.

ASSISTANT: Please give me a moment.

USER: Ok, please take the time you need.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: That is ok, thank you for assisting me.

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.