function changeImages() {
    var imgName;
    var obj;

    nTick--;
    if (nTick <= 0) {
        nTick = 60;
        nImage++;
        if (nImage > 12)
            nImage = 1;
    }
    else if (nTick < 7) {
        imgName = "img" + nTick.toString();
        
        obj = document.getElementById(imgName);
        if (obj != null) {
            var _obj = obj;
            var _nTick = nTick;
            var _nImage = nImage;
            $(obj).fadeOut('slow', function () { imgFadeIn(_obj, _nTick, _nImage); });
        }
    }

}
function imgFadeIn(_obj, _nTick, _nImage) {
    _obj.src = images[_nTick][_nImage].src;
    $(_obj).fadeIn('slow');
}

var nImage = 2;
var nTick = 30;
var images = new Array();
var img;
var imgName;
for (var n = 1; n <= 6; n++) {
    images[n] = new Array();
    for (var m = 1; m <= 12; m++) {
        imgName = "images/img" + n.toString() + "_" + (m < 10 ? "0" : "") + m.toString() + ".jpg";
        img = new Image();
        img.src = imgName;
        images[n][m] = img;
    }
}

setInterval("changeImages();", 500);