You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Could you please let me know, on which name it has been reserved?

USER: Donald Lee here.

ASSISTANT: Wait a minute, we will check and revert you.

USER: Ok.

ASSISTANT: Sorry, we could not find any reservation on your name.

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for reaching our agency.