You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I want to change my reservation due to some problems I am unable to travel those dates, can you please change my travel dates?

ASSISTANT: Sure, I will help you with that.

USER: Thanks.

ASSISTANT: Can I have your name please for checking your reservation?

USER: Sure, my name is Steven Hill.

ASSISTANT: Ok, please be hold on for a moment to check your reservation status.

USER: Ok.

ASSISTANT: Sorry Steven Hill, no reservation has found under your name to change.

USER: It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a great day.