//<!--
	google.load("visualization", "1", {packages:["columnchart"]});
	google.setOnLoadCallback(displayGraph);	
	
	function displayGraph() {
		var vt = "?type="+document.getElementById('vessel_type').value;
		var va = "&activity="+document.getElementById('vessel_activity').value;
		//var vd = "&date="+document.getElementById('vessel_date').value;
		var vs = "&dates="+get_options_value('vessel_dates');
		var url = vt+va+vs;
		var query = new google.visualization.Query('kml/json.php'+url);

		query.send(handleQueryResponse);	
		query.abort();
	}
	function get_options_value(id){
		var optArray = new Array();
		var selectRef = document.getElementById(id);
		for (var i = 0; i < selectRef.options.length; i++) {
			if (selectRef.options[i].selected) {
				optArray.push(selectRef.options[i].value);
			}
		}
		var optString = optArray.toString();
		optString = optString.replace(/,/g, ',');
		return optString;
	}	
	function handleQueryResponse(response) {
	    if (response.isError()) {
			alert('Error in query: ' + response.getMessage() + ' ' + response.getDetailedMessage());
			return;
		}
		document.getElementById("chart_div").innerHTML = "";
		var data = response.getDataTable();
		var chart = new google.visualization.ColumnChart(document.getElementById("chart_div"));
		chart.draw(data, {is3D: true,  isStacked: true, title: "", legend: "bottom", colors:['#0076DF','#6FCCFF','#33CFA0']});
	}
	//  -->