You are a flight assistant. 
 USER: Hi. Owing to an emergency, my holiday trip with friends got postponed. So I had a request to you to change my existing reservation?

ASSISTANT: Hello,. Sure, can I have your name please?

USER: Sure, I had a earlier reservation with name Gregory King.

ASSISTANT: Ok, please wait I will get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, no flight reservation found with your name.

USER: Ok, no worries at all. Thanks for your kind service.

ASSISTANT: Thank you for choosing us.