You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Sure, can I know your name please?

USER: Sure, my name is Steven Miller.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Oh! It's ok no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.