feature attributes in featureselected

[noog]

hello
if i use the function "featureselected" the string feature.attributes.id_test; is undefined
how can i get this value or another one from "attributes" of a feature ?

   for (var i=0; i<data.length; i++) {
            var lon = data[i].x;
            var lat = data[i].y;
            var id_poi = data[i].id_poi; // --> i have the value

            var f = new OpenLayers.Feature.Vector(
                new OpenLayers.Geometry.Point( lon, lat ).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject()),
                {
                    "id_test":data[i].id_poi // --> i add the value
                }
            );  

            features.push(f);
           }
    couche_markers.addFeatures(features); // add POI

// active control
click = new OpenLayers.Control.SelectFeature( [couche_markers], { clickout: false, toggle: false});

map.addControl(click); 
            couche_markers.events.on({ 
        "featureselected": function(e) { 
            var feature = e.feature;
            id_poi = feature.attributes.id_test;
        console.log("show id poi"+id_poi"; //--> ERROR the variable is undefined
        } 
    }); 

[acanimal]

Once clustered each cluster is a feature wich contains the set of features near to that point.
"Original" features are stored withint the feature.cluster attribute. Take a look on that.

[noog]

ok thanks
i can access my value like this
couche_markers.events.on({
"featureselected": function(e) {
var feature = e.feature.cluster[0].data;
var cpt_cluster = e.feature.cluster.length;
if(cpt_cluster == 1)id_poi = e.feature.cluster[0].data.id_test;
}
});

now i want to have a specific external graphic when there is only one poi
so i have created this rule but i don't know how to get one of the feature.cluster value here

externalGraphic: "/drawable-hdpi/theme/${cat_poi}_poi.png",
instead of
externalGraphic: "/drawable-hdpi/theme/Cat_20_02_poi.png",

thanks :)

        // Define three rules to style the cluster features.
        var oneRule = new OpenLayers.Rule({
            filter: new OpenLayers.Filter.Comparison({
                type: OpenLayers.Filter.Comparison.LESS_THAN,
                 property: "count",
                value: 2
            }),
            symbolizer: {
                 fillOpacity: 1, 
               opacity : 1,
                externalGraphic: "/drawable-hdpi/theme/Cat_20_02_poi.png",
                graphicHeight: 50, graphicWidth: 50, graphicXOffset:-25, graphicYOffset:-25
            }
        });