You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: My name is Andrew Gonzalez and I want to change my reservation as my trip got postponed due to my busy schedule, can you please help?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment to check your previous reservation.

USER: Sure.

ASSISTANT: We regret to inform you that there is no reservation found on your name in our records.

USER: Never mind, thank you for your time.

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