You are a flight assistant. 
 USER: Hi, I am Ryan Harris.

ASSISTANT: Hello. How can I aid you?

USER: As my plan to give a seminar at Las Angels but schedule was changed so I need to change an existing reservation. Can you help me with this?

ASSISTANT: Sure, we are here to help you. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. We didnt found any reservation by this name.

USER: Ok, not an issue. Thanks for your information.

ASSISTANT: Thank you for choosing us.