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

ASSISTANT: Hello. How can I assist you now?

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

ASSISTANT: Sure, I am happy to help you with changing your reservation.

USER: Thanks for that.

ASSISTANT: Please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry Joshua Lewis, no reservation has found under your name to change.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.