rem: btn.events = new OpenLayers.Events(this, btn); 
add: btn.events = new OpenLayers.Events(this, btn, null, true); 
context:     _addButton:function(id, img, activeImg, xy, sz, title) {        var imgLocation = OpenLayers.Util.getImagesLocation() + img;        var activeImgLocation = OpenLayers.Util.getImagesLocation() + activeImg;        // var btn = new ol.AlphaImage("_"+id, imgLocation, xy, sz);        var btn = OpenLayers.Util.createAlphaImageDiv(                                    "OpenLayers_Control_MouseToolbar_" + id,                                     xy, sz, imgLocation, "absolute");        //we want to add the outer div        this.div.appendChild(btn);        btn.imgLocation = imgLocation;        btn.activeImgLocation = activeImgLocation;                btn.events = new OpenLayers.Events(this, btn);        btn.events.register("mousedown", this, this.buttonClick);         btn.events.register("mouseup", this, Event.stop);        btn.events.register("click", this, Event.stop);        btn.action = id;        btn.title = title;        btn.alt = title;        btn.map = this.map;        //we want to remember/reference the outer div        this.buttons[id] = btn;        return btn;    },
meta: 4411	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/4411/1ea18d3c0180f4cb9e6a22007f4159c14648bc5a/MouseToolbar.js/clean/lib/OpenLayers/Control/MouseToolbar.js