You are a flight assistant. 
 USER: Hello. I am Scott Lewis.

ASSISTANT: Hello. How can I help you?

USER: I have planned to spend a time with my family, but unfortunately I did not get any leaves. So, can you please help me to change my reservation?

ASSISTANT: Sure, I am here to help you. Sorry, there is no reservation found for you.

USER: Oh! OK no problem.

ASSISTANT: Thank you.Have a good day.

USER: Thank you for your help.