Please could someone help direct me on how to use a button, to call a function in a php file?

Question

Like using a click event to call a function that increments a value by a step height eg function Extrapolate($x) {$y=++$y;
echo $y +$×}. So I wish whence I click a button, after having passed in a parameter, the changing result be printed out on the page each time

Answer 1

When I try passing through the html button method, nothing works.