You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Brian Gonzalez. I have to change my travel dates in the past ticket, can you please help me to do that?

ASSISTANT: Sure, I am glad to help you. Sorry, there is no reservation with your name to change further.

USER: It's ok, thank you for checking my ticket status.

ASSISTANT: You are welcome.