You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Myself Michael Phillips, due to some business meeting I am going to change my existing reservation. Can you please help me in changing my reservation?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure, I will wait for your response.

ASSISTANT: Michael, there is no reservation found under your name.

USER: Not an issue, anyhow thank you very much for your help.

ASSISTANT: Thank you for contacting us.