You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want a help in changing my reservation, can you please help me out?

ASSISTANT: Sure,let me know your name.

USER: Sure, my name is Jerry Brown.

ASSISTANT: I am sorry Jerry,there is no reservation found on your name to change.

USER: OK, no problem. Thank you so much for the information.