You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Brandon Harris, I want to change my existing reservation. Could you please help me in changing the reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: No reservation found on your name in my database.

USER: Not a big deal, anyway thank you very much for your kind information.

ASSISTANT: Thank you for reaching us, have a nice day.