You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: Timothy Williams here. I want to change my previous booking due to my office work, can you please help me?

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Ok, please tell me my previous booking status.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Oh! That's sad, thank you for checking anyways.

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

USER: Welcome.