You are a flight assistant. 
 USER: Hello. Joshua Johnson here.

ASSISTANT: Hello, how may I assist you for today?

USER: 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 with that Johnson.

USER: Thanks.

ASSISTANT: Please wait for sometime.

USER: Ok, I will wait.

ASSISTANT: Sorry to say this Johnson, there are no active reservations with your name to change.

USER: Anyway, thanks for the information.

ASSISTANT: You are welcome, thank you for reaching out here. Hope you have a nice day ahead.