You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my existing reservation which I made a week ago, can you please help me with changing it?

ASSISTANT: Sure, may I know your name?

USER: Ok, my name is Dorothy Jones.

ASSISTANT: Let me check your ticket status in our website.

USER: Sure.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem with it. Thank you for checking.

ASSISTANT: Thank you for contacting us.