information on hover and multiple feature selection - openlayers-3

Question

I'm working with OpenLayer 3.1.1, starting from this example: http://openlayers.org/en/v3.1.1/examples/vector-layer.html?q=hover
I would like show information on mouse hover and select multiple feature on click. Going to add the second feature to the selection it is selected twice. Why?
var selectClick = new ol.interaction.Select({
condition: ol.events.condition.click,
addCondition: ol.events.condition.shiftKeyOnly ,
toggleCondition: ol.events.condition.never,
removeCondition: ol.events.condition.altKeyOnly,
});
select = selectClick;
map.addInteraction(select);
var highlightStyleCache = {};
var featureOverlay = new ol.FeatureOverlay({
map: map,
style: function(feature, resolution) {
var text = resolution < 5000 ? feature.get('DIVISION') : '';
if (!highlightStyleCache[text]) {
highlightStyleCache[text] = [new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#f00',
width: 1
}),
fill: new ol.style.Fill({
color: 'rgba(255,0,0,0.1)'
}),
text: new ol.style.Text({
font: '12px Calibri,sans-serif',
text: text,
fill: new ol.style.Fill({
color: '#000'
}),
stroke: new ol.style.Stroke({
color: '#f00',
width: 1
})
})
})];
}
return highlightStyleCache[text];
}
});
var highlight;
var showCheckbox = document.getElementById('infoShow');
var displayFeatureInfo = function(pixel) {
var feature = map.forEachFeatureAtPixel(pixel, function(feature, layer) {
return feature;
});
if (showCheckbox.checked) {
if (feature) {
if (feature.getKeys()=='geometry,COORDINATOR COUNTRY') {
infoBox.innerHTML = '<strong>Coordinator Country: </strong>' + feature.get('COORDINATOR COUNTRY')+ '<br>'+ '<br>';
}
else {
infoBox.innerHTML = '<strong>Area: </strong>' + feature.get('AREA') + '<br>'+'<strong>Marine division: </strong>' + feature.get('DIVISION');
}
} else {
infoBox.innerHTML = ' '+'<br>'+ '<br>';
}
if (feature !== highlight) {
if (highlight) {
featureOverlay.removeFeature(highlight);
}
if (feature) {
featureOverlay.addFeature(feature);
}
highlight = feature;
}
}
};
$(map.getViewport()).on('mousemove', function(evt) {
var pixel = map.getEventPixel(evt.originalEvent);
displayFeatureInfo(pixel);
});