(function () {
	function setStyleForSelector(selector, display) {
		Array.prototype.forEach.call(document.querySelectorAll(selector), function (el) {
			el.style.display = display;
		});
	}

	Array.prototype.forEach.call(document.querySelectorAll('circle'), function (el) {
		el.addEventListener('mouseenter', function () {
			setStyleForSelector('line[data-from="' + el.getAttribute('id') + '"]', '');
			setStyleForSelector('line[data-to="' + el.getAttribute('id') + '"]', '');
		});

		el.addEventListener('mouseout', function () {
			setStyleForSelector('line[data-from="' + el.getAttribute('id') + '"]', 'none');
			setStyleForSelector('line[data-to="' + el.getAttribute('id') + '"]', 'none');
		});
	});
})();
