Demonstrate mouseover tooltip
When the user hovers over a datum, the tooltip will show for the datum, and the series will be selected. Not ideal since it is not a series focus, and the tooltip is not about the series.
by dlaliberte
HTML
<script src="http://www.google.com/jsapi?ext.js"></script>
<div id="curve_chart" style="width: 600px; height: 350px"></div>
JavaScript
function drawChart() {
var data = google.visualization.arrayToDataTable([
...