You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help 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. Kindly share your name.

USER: Dorothy Hall here.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: No problem, Thanks for the information.

ASSISTANT: Thanks for reaching us.