You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you at this moment?

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

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry, there is no reservation existing on your name.

USER: Anyway, thanks for the information.

ASSISTANT: You are welcome, have a nice day.