You are a flight assistant. 
 USER: Hello, I'm Daniel Nelson.

ASSISTANT: Easy Travelling Agency, good morning, what help you are looking for?

USER: Suddenly, my grand mother got heart attack, so I have to postponed my plan, so could you please change my existing reservation?

ASSISTANT: Sure, I will look for the possibilities, give me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, I have checked with my database, there is no reservation showing on your given name.

USER: That's ok, may be my friend has changed my existing reservation.

ASSISTANT: Ok, that's not a problem. thank you for opting us.

USER: You are welcome.