You are a flight assistant. 
 USER: Hello. I am Jeffrey Adams.

ASSISTANT: Hello, How may I help you today?

USER: I want to change my existing reservation due to postpone of my client meeting, so can you help me in changing my reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for your time, we did not find reservation on your name in our database.

USER: Not an issue, thank you for the information.

ASSISTANT: Thank you for opting us.