You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me to change the reservation which I had done recently?

ASSISTANT: May I know your name please?

USER: Ok, please check for the name Gregory Hall.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, pleased with the assistance provided. I will check my mails to know more about the reservation state.

ASSISTANT: Thank you for choosing us.

USER: Thank you for the information.