rem: if (this.popup != null) { this.layer.map.removePopup(this.popup); 
add: if ((this.layer != null) && (this.layer.map != null)) { if (this.popup != null) { this.layer.map.removePopup(this.popup); } 
context:     destroy: function() {        //remove the popup from the map        if (this.popup != null) {            this.layer.map.removePopup(this.popup);        }        this.events = null;        this.layer = null;        this.id = null;        this.lonlat = null;        this.data = null;        if (this.marker != null) {            this.marker.destroy();            this.marker = null;        }        if (this.popup != null) {            this.popup.destroy();            this.popup = null;        }    },
meta: 2032	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2032/fc366b73fe5923273e8fced6079c546fd780fc54/Feature.js/clean/lib/OpenLayers/Feature.js