how to add an "onclick" function to a marker?

I have a marker such as this var feature = new OpenLayers.Feature.Vector( new OpenLayers.Geometry.Point( lng,lat ).transform(epsg4326, projectTo), {description:'something'} , {externalGraphic: 'somepic.png', graphicHeight:34, graphicWidth: 21, graphicXOffset:0, graphicYOffset:0 }); vectorLayer.addFeatures(feature); map.addLayer(vectorLayer); i was wondering if there is a way to add onclick function to the markers, so an example use would be something like feature.onClick(function (){ alert("clicked"); });