Google chart tooltip add action

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>

	 	<script>
		

	function drawChart() {
	 	var data = new google.visualization.DataTable();
	 	//var clicktip='';
	 	
	 	
	 	data.addColumn('number', 'Month');
	 	data.addColumn('number',2017);
                data.addColumn('number',2018);
	 	
	 	
	 	//data.addColumn('number', 'sessionkey');
		//data.addColumn({role: 'tooltip', type: 'string', p: {html:true,trigger:'selection'});
		//data.addColumn({type:'string', role:'tooltip',p: {html:true}});  
		


    data.addRows([
      	
      		[{v: 3, f:'March',z:'242018'},null,8,]	,
      	
      		[{v: 6, f:'June',z:'242019'},null,13,]	,
      	
      		[{v: 7, f:'July',z:'242020'},null,10,]	,
      	
      		[{v: 11, f:'November',z:'272793'},null,5,]	,
      	
      ]);
     
    
     
    
     var options = {
        hAxis: {
            title: 'Month',
            showTextEvery: 1,
            legend: 'none',
            
            ticks: [{
                v: 1,
                f: 'Jan'
            }, {
                v: 2,
                f: 'Feb'
            }, {
                v: 3,
                f: 'Mar'
            }, {
                v: 4,
                f: 'Apr'
            }, {
                v: 5,
                f: 'May'
            }, {
                v: 6,
                f: 'Jun'
            }, {
                v: 7,
                f: 'Jul'
            }, {
                v: 8,
                f: 'Aug'
            }, {
                v: 9,
                f: 'Sep'
            }, {
                v: 10,
                f: 'Oct'
            }, {
                v: 11,
                f: 'Nov'
            }, {
                v: 12,
                f: 'Dec'
            }]
        },
          vAxis: {
         	 title: 'Participation',
         	 minValue:0
         },
         title: "Chart for School 1",
         displayAnnotations: true,
         curveType: 'function',
         pointSize: 14,
         tooltip: {isHtml: true,trigger: 'selection'},
         legend: 'none',
    }

     var chart = new google.visualization.LineChart(document.getElementById('chart2_div_1_1'));
     
    
  
  
     
     chart.draw(data, options);
  
     
     	chart.setAction({
            id: 'chart2_div_1_1',
            text: 'View Details',
            action: function() {
            	// selection  = chart.getSelection();
            	// selectedRow = selection[0].row;
            	
            	 var selectedItem = chart.getSelection()[0].row;
         alert(data.getValue(selectedItem, 0));   	 
            	  
            	  var value = data.getValue(selectedItem, 0);
            	  
            	 	alert('The user selected ' + value);
            	
            
           window.open('viewStat.cfm?sessionKey='+selectedRow);
            
            }
        });
        
    
    //google.visualization.events.addListener(chart, 'click', getsessionkey);
        
    }
   
    
    google.load("visualization", "1", {
    packages: ["corechart"]
});


google.setOnLoadCallback(drawChart);


 </script>

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