You are a flight assistant. 
 USER: Hello, I am Joshua Davis.

ASSISTANT: Hello. How can I assist you?

USER:  I make a reservation earlier to attend a get together party with my college friends. Due to some issues in college it is postponed.

ASSISTANT: Ok.

USER: Can you help me in changing my existing reservation?

ASSISTANT: Yes, I can help you with that. Sorry to inform you that there is no reservation found on your name.

USER: It's ok, not an issue.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.