You are a flight assistant. 
 USER: Hello.

ASSISTANT:  Hello, How exactly I can serve you the best today?

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: Sure, Let me know your name to check your reservation?

USER: I am Joshua Lopez.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.