You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Kevin Davis. I just want to change an existing reservation, due to my exams dates were changed. Can you help me with Changing reservation?

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

USER: Sure, take your time.

ASSISTANT: Sorry Kevin, there are no flight tickets reserved on your name.

USER: Not an issue. Thank you for reaching us, have a nice day.

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