Write some Software

I need a very simple code to be designed for a webpage that I am going to be building, I simply need this code to be created and sent to me. What it needs to do: On the webpage there will be nothing but an image on the background. Once a user reaches my webpage, I will need a popup to appear on the screen from the browser (blocking access to the close tab or close browser buttons on certain browsers) once this popup appears there should be a 'OK' button, once the user clicks on the 'OK' button, I want it to trigger the image to go into full screen mode. Of course, the user will have the option to click escape to get away from the full screen mode, but I want this to trigger the same popup or another popup to appear on the page again, which leads back to the same situation where the user goes back into full screen mode once they click 'OK', creating a loop for the user to be trapped in. The code is all that needs to be provided, it should be made in a simple format and the text in the popup will be provided. The code should be able to integrate to our webpage with HTML without causing any issues. Feel free to contact me for any additional questions, Thank you.