You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you now?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Can you please share your name to check with your existing reservation status?

USER: My name is Alexander Brown.

ASSISTANT: Ok, please be on hold for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Alexander Brown, there is no active reservation available in our database by your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.