rem: getComputedURL: function( elem, attr ) { var url = this.getComputedStyle( elem, attr ); return ( url == "none" ) ? url : url.replace( /^url\("?([^")]+)"?\)/i, "$1" ); 
add: getComputedURL: function( elem, prop ) { var url = elem.ownerDocument.defaultView.getComputedStyle( elem, '' ).getPropertyCSSValue( prop ); return ( url.primitiveType == CSSPrimitiveValue.CSS_URI ) ? url.getStringValue() : null; 
context:     getComputedURL: function( elem, attr ) {         var url = this.getComputedStyle( elem, attr );         return ( url == "none" ) ? url : url.replace( /^url\("?([^")]+)"?\)/i, "$1" );    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/3c1e4a46866e615f1414c80bb950daa41befae8f/nsContextMenu.js/buggy/xpfe/communicator/resources/content/nsContextMenu.js