You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you for today?

USER: This is with reference to my booking flight number 1003  with your agency on 03/10 date. I'm sorry to inform you that I won't be able to make it due to some reason, hence I would like to cancel my booking.

ASSISTANT: Sure, I feel doleful about it. I will definitely help you about it. Can you please help by providing your name to check the previous reservation in our data?

USER: Sure, my name is Gregory Green and the reservation which I want to cancel is also done on the same name.

ASSISTANT: Sorry Green, I can not find any reservation on your name in our data because your validity of cancellation was completed. It might be automatically deleted in our database.

USER: Ok, I feel gloomy at this situation. I don't have any possibility to deal with this issue, anyway thank you for succour.

ASSISTANT: My pleasure, thank you for employ our service. Hope you have a great day.