You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: I will help you, please wait a moment.

USER: Ok, sure.

ASSISTANT: Ok, thank you for waiting. I am sorry as there is no reservation been found. So I can not help you?

USER: Ok, fine thank you for checking.