You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Scott.

ASSISTANT: Ok Scott, what can I do for you?

USER: I want to change my existing reservation, as my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, I will help you. Please wait a while. I will revert you.

USER: Sure.

ASSISTANT: Sorry Scott, there is no reservation found with your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.