You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Stephen Robinson here. Can you help me in change of my flight ticket reservation?

ASSISTANT: Sure, I can help you with it. That's part of my job. Please wait for a moment till I check with your previous booking.

USER: Sure.

ASSISTANT: I am so sorry to inform you about it, but there is no reservation found under your name.

USER: Not a problem. Thanks for checking.

ASSISTANT: Thank you for choosing us, have a great day ahead.