[danik.js]

window.addEventListener('click', function(){

    var checkboxes = new Array(4);
    var states = new Array(4);
    var onclick = function() {
        var args = new Array(4);
        for (var i = 0; i < checkboxes.length; i++) {
            var checkbox = checkboxes[i];
            if (this === checkbox) {
                args[i] = Number(this.checked);
            } else {
                args[i] = states[i];
                checkbox.checked = states[i];
            }
        }
        Polygon.apply(window, args);
    };

    for (var i = 0; i < checkboxes.length; i++) {
        var checkbox = document.getElementById('p' + (i + 1));
        checkbox.addEventListener('click', onclick, false);
        checkboxes[i] = checkbox;
        states[i] = checkbox.checked;
    }

}, false);