You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: Can you help me to change my recent reservation?

ASSISTANT: Sure, I am here to help you out with that.

USER: Ok.

ASSISTANT: May I know your good name please to track the details?

USER: Andrew Martinez here.

ASSISTANT: Ok, Please allow me a moment to check for the previous reservation in our database.

USER: Please go ahead.

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

USER: Ok, no issue. Thank you for the help.

ASSISTANT: Thank you for your presence. We hope to serve you again.