You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

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

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

USER: Sure, I will wait for your response.

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

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

ASSISTANT: Thank you for contacting us.

USER: Welcome.