itemmouseover: Function

Sets the mouseover event handler for the legend, which is triggered when the user moves the mouse(input device) over a legend item. After the event is triggered, the event related data is passed as a parameter to the assigned event handler. Parameters passed to the function are shown in the Event Object section below.

var  chart =  new  CanvasJS.Chart("container",
{
 .
 .
 legend: {
  
   itemmouseover: function(e){
          alert( "Mouse moved over the legend item");
        }

 },

 .
 . 
});
chart.render();

e:{ 
	x, 
	y,
        chart,
	dataPoint, 
	dataSeries, 
	dataPointIndex, 
	dataSeriesIndex
}