You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I hand helping to you?

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

ASSISTANT: Sure, I am happy to assist you in that one. May I know your name for checking?

USER: I have reserved my flight ticket with name Ryan Parker.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT:  Ryan Parker, there is no ticket found to cancel it.

USER: Ok, fine not an issue. Thank you for checking.

ASSISTANT: Welcome.