You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what sort of help are you seeking from me?

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

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Please allow me a moment to check for the previous reservation in our data base.

USER: Sure, I will wait for your response.

ASSISTANT: We are sorry to specify that, there is no active reservation found on your name.

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

ASSISTANT: Thanks for choosing us, have a nice day.

USER: Welcome.