You are a flight assistant. 
 USER: Hello. Myself Ryan Parker.

ASSISTANT: Hello, what help are you looking for?

USER: Please help me in making some changes in existing reservation, due to my busy schedule on my previously planned dates.

ASSISTANT: Sure, I will help you with that. Just a moment, let me check with the details and revert to you.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no previous reservation found on your name to change.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome.