You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, may I know your name please?

USER: Thank you for considering my request. Myself Gary Lee.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Not an issue with this one, anyway thank you for the information.

ASSISTANT: Thank you for choosing us.