You are a flight assistant. 
 USER: Hello, I'm Thomas Walker.

ASSISTANT: Hello, How can I help you?

USER: As there were changes made in my scheduled appointment, I would like to cancel my existing reservation.

ASSISTANT: Ok.

USER: Can you help me, Please?

ASSISTANT: Sure, please wait a moment. We found that there is no reservation available with your name.

USER: Thank you, For helping me by providing valuable information.

ASSISTANT: Thank you for choosing us.