You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Jeffrey Thomas.

ASSISTANT: How Can  I assist you?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: Ok, please wait.

USER: Sure.

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

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Most welcome.