rem: this.layerContainerDiv.style.left = (originPx.x - newPx.x) + "px"; this.layerContainerDiv.style.top  = (originPx.y - newPx.y) + "px"; 
add: if ((originPx != null) && (newPx != null)) { this.layerContainerDiv.style.left = (originPx.x - newPx.x) + "px"; this.layerContainerDiv.style.top  = (originPx.y - newPx.y) + "px"; } 
context:     centerLayerContainer: function (lonlat) {        var originPx = this.getViewPortPxFromLonLat(this.layerContainerOrigin);        var newPx = this.getViewPortPxFromLonLat(lonlat);        this.layerContainerDiv.style.left = (originPx.x - newPx.x) + "px";        this.layerContainerDiv.style.top  = (originPx.y - newPx.y) + "px";    },
meta: 1027	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1027/7ecc62e55a93e556abbbb1b2bd8e7cb2c34f0f40/Map.js/clean/lib/OpenLayers/Map.js