You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I am Elizabeth Williams. Can you please help me in changing my recent reservation?

ASSISTANT: Sure, please wait for a minute.

USER: Ok, sure.

ASSISTANT: Sorry, I could not find any reservation with your name in our database.

USER: Ok, fine thank you for checking.

ASSISTANT: My pleasure.