You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: William Jackson here. Due to inconvenience of my work, I wan to change my reservation. Can you please help me for that?

ASSISTANT: Ok, please wait a moment I will revert you back with the proper information. Thanks for your time, there is no reservation found on your name to change it.

USER: Anyway, thanks for the information.

ASSISTANT: Thanks for contacting us, have a good day.