You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Samuel Smith. I want to change my reservation which I have done last week due to my schedule got postponed. Help me about it.

ASSISTANT: Sure, I will help you with that, please hold on for a moment to check your reservation status.

USER: Ok, sure.

ASSISTANT: Smith, I did not find any reservation with your name in my database.

USER: Ok, fine it might not be booked properly at the time of booking. Anyway thank you for the help.

ASSISTANT: It's my pleasure, have a nice day.