Meralco Bill Calculator (PHP/MySQL)

Hey guys, this is a simple application coded with core PHP and MYSQL using PDO. Summer months in the Philippines is so hot we had to use at least two fans at night just to get good sleep. I was a little worried about our electricity consumption so I made this simple app to compute how much we have to pay even before the bill arrives. Basically, you just have to input a couple of details you can find at the back of your latest Meralco bill so you can be sure that the calculated amount is accurate. After that, all you have to do is input the previous reading (also can be found at the back of your Meralco bill) then your current reading which you can find on your Meralco meter (the big round thing that has numbers in the middle). Then click CALCULATE! As I said, this is a very basic PHP application (I did it less than an hour) but it should be enough to give you an introduction to Object Oriented PHP and PDO connection. Cheers!