(function() {
    var ERROR_IMG = "/products/missing_thumb.png";

    function CheckImg(img) {
        var tester = new Image();
        tester.onerror = function() {
            if (img.src.indexOf(ERROR_IMG) < 0){
                img.src = ERROR_IMG;
            }
        };
        tester.src = img.src;
    }

    var img, n = document.images.length;
    for (var i = 0; i < n; i++) {
        img = document.images[i];
        if (img.parentNode.className.indexOf("product-img") >= 0) {
            CheckImg(img);
        }
    }
})();