You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Paul Jackson here.

ASSISTANT: Paul Jackson, how may I assist you?

USER: I just want to change my previous reservation due to postponed of my exams, can you please help me with that?

ASSISTANT: Sure, I am here to help you. Hold on for a moment. Let me check in our data base.

USER: Sure.

ASSISTANT: Sorry Paul Jackson, there are no flights reserved on your given name formerly.

USER: No problem, thank you for the information.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.