You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Helen Walker. Can you please help me in change my recent reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok, sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for choosing us.