You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation. Can you help me?

ASSISTANT: Sure, I am here to help you. Please provide your name for checking purpose.

USER: Alexander Green here.

ASSISTANT: Sorry Alexander Green, no reservation found on your name in our data list.

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for approaching us, have a great day.