allMarkers = new Array();
        addMarker = function (x,y)
        {
            size = new OpenLayers.Size(10,17);
            offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
            icon = new OpenLayers.Icon('http://boston.openguides.org/markers/AQUA.png',size,offset);
            allMarkers.push(new OpenLayers.Marker(new OpenLayers.LonLat(x,y),icon.clone()));
            //myMark.setOpacity(1.0);
            var markerCount = allMarkers.length - 1;
            if(markerCount == 0){
                allMarkers[0].events.register("mousedown", allMarkers[0], function(evt){ markerLayer.removeMarker(allMarkers[0]);});
            }else if(markerCount == 1){
                allMarkers[1].events.register("mousedown", allMarkers[1], function(evt){ markerLayer.removeMarker(allMarkers[1]);});
            }else if(markerCount == 2){
                allMarkers[2].events.register("mousedown", allMarkers[2], function(evt){ markerLayer.removeMarker(allMarkers[2]);});
            }else if(markerCount == 3){
                allMarkers[3].events.register("mousedown", allMarkers[3], function(evt){ markerLayer.removeMarker(allMarkers[3]);});
            }
            markerLayer.addMarker(allMarkers[markerCount]);
        }