function replaceAt(str, index, char) {
    return str.substr(0, index) + char + str.substr(index + char.length);
}

// ------------------------------
// Preload images Function
// ------------------------------
(function ($) {
    var cache = [];
    // Arguments are image paths relative to the current page.
    $.preLoadImages = function () {
        var args_len = arguments.length;
        for (var i = args_len; i--; ) {
            var cacheImage = document.createElement('img');
            cacheImage.src = arguments[i];
            cache.push(cacheImage);
        }
    }
})(jQuery)

var seqCount = 4;
var seqSpeed = 600;
var seqIndex = 1;
var seqTimer;
var seqObject;
var seqDefaultSrc;

$(document).ready(function () {

    // ---------------------------------
    // Animazione sequenza su immagini 
    // sezione People, con preload
    // ---------------------------------
    $('.people IMG').each(function () {
        for (i = seqCount; i > 1; i--) {
            src = $(this).attr('src');
            src = replaceAt(src, src.length - 5, String(i));
            jQuery.preLoadImages(src);
        }
    });
    $('.people IMG').hover(
    // MouseIn
                function () {
                    seqObject = $(this);
                    seqDefaultSrc = seqObject.attr('src');
                    seqTimer = setInterval(
                        function () {
                            if (++seqIndex > seqCount) { seqIndex = 1; }
                            seqObject.attr('src', replaceAt(seqDefaultSrc, seqDefaultSrc.length - 5, String(seqIndex)));
                        }, seqSpeed);
                },
    // MouseOut
                function () {
                    seqObject.attr('src', seqDefaultSrc);
                    clearInterval(seqTimer);
                    seqIndex = 1;
                }
            );

});