You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Please wait a while.

USER: Ok, I will wait.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for opting us.