Google donut chart

Fixed: 1. Markup - Separated HTML, CSS and JavaScript code; 2. :after pseudo-element inside #chart_div for donut hole; 3. Hide tooltip when mouseover on "hidden" slice.

HTML

<script src="http://www.google.com/jsapi?fake=.js"></script>
<div id="chart_div"></div>

JavaScript

google.load("visualization", "1", {
    packages: ["corechart"]
});
google.setOnLoadCallback(drawChart);

function drawChart() {
    var data = new google.visualization.DataTable();
    data.addColumn('string', 'FrequencyName');
    data.addColumn('number', 'Frequency');
    
    data.addRows([
        ['A', 1],
        ['B', 2],
        ['C', 2],
        ['D', 4],
        ['E', 4]
        ]);
    var options = {
        width: 450,
        height: 300
       
    };
    var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
    chart.draw(data, options);
}