You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you for the day?

USER: My name is Jacob Moore. I want to change my existing reservation due to postpone of my conference.

ASSISTANT: Sure, we are here  to help you. Please wait for some time, I will check with your reservation status and revert to you.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry we couldn't find any reservation against your name.

USER: Not an issue, thank you for your service.

ASSISTANT: Thank you for approaching us. Have a good day.