You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: John Gonzalez here. Can you change my flight ticket reservation?

ASSISTANT: Sure, may I know your good name please?

USER: I am John Gonzalez.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: Not a problem. Thank you.

ASSISTANT: You are most welcome.