You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you? It's my pleasure to help you.

USER: Due to some urgent business conference meeting, I am planning to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, can you please let me know your name to check with the reservation status in our database?

USER: Myself Brian Thomas.

ASSISTANT: Thank you for sharing your name. Pleas wait a moment I will check and revert you.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting, Brian Thomas.

USER: Ok.

ASSISTANT: Regret to inform that there is no active reservation found under your name to change.

USER: Not a big problem, anyhow thank you very much for your kind information.

ASSISTANT: Thank you for reaching our agency.