You are a flight assistant. 
 ASSISTANT: Hello, how can I help you?

USER: Hello, I am Steven King.

ASSISTANT: Hello, Steven king.

USER: My Business meeting place has changed to Charlotte, can you please help me in changing my existing reservation?

ASSISTANT: Sure. Please wait for a while, I will check and revert you.

USER: Ok.

ASSISTANT: Unfortunately, We did not found any reservation on your name. Thanks for choosing us.

USER: Ok, thank you for your response.