You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brian Thomas.

ASSISTANT: How can I assist you?

USER: Due to some urgent entrepreneur meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure Thomas, please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Not a big deal, anyway thank you very much for giving the information.

ASSISTANT: Thank you for approaching us.