You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I be your helping hand today?

USER: I already have an reservation to attend at my meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation. Can you help me?

ASSISTANT: Ok. To change the reservation, may I have your name?

USER: Justin Lopez here.

ASSISTANT: Thanks for your time. Sorry, we did not find any reservation on your name.

USER: No problem, Thank you.

ASSISTANT: Thank you for choosing us.