function isScrolledIntoView(elem) {
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom >= docViewTop) && (elemTop <= docViewBottom));
}

function checkToLoad() {
    $(".ThumbnailView img.toload").each(function() {
        if (isScrolledIntoView(this)) {
            var $img = $(this);
            $img
                       .attr("src", $img.attr("lazysrc"))
                       .removeClass("toload");
        }
    });
}

$(function() {
    $(window).resize(function() {
        checkToLoad();
    });

    $(window).scroll(function() {
        checkToLoad();
    });

    checkToLoad();
});