var itemsLeft=new Array();
var t;

function impressThem(count) {
    if(count==undefined) {
        count = 24;
    }
    var i = 1;
    for (i=0;i<count;i++) {
        $("#portfolio").css("background","0").append('<div id="s'+i+'"><span><\/span><\/div>');
        itemsLeft[i]=i;
    }
    $("#portfolio div span").hide();
    showNext();
}

function showNext() {
    var boxSize = $("#portfolio span").width();
    var containerSize = $("#portfolio").width();
    var boxesInRow = Math.ceil(containerSize/boxSize);
    if (itemsLeft.length>0) {
            var randomnumber = Math.floor(Math.random()*itemsLeft.length);
            var i = itemsLeft[randomnumber];
            var col = i % boxesInRow;
            var row = Math.floor(i / boxesInRow);
            var x = -(col * boxSize);
            var y = -(row * boxSize);
            
            $("#portfolio #s"+i+" span").css("background-position",x+"px "+y+"px").fadeIn(1000);
            itemsLeft.splice(randomnumber,1);
            t = setTimeout("showNext()",50);
    } else {
        clearTimeout(t);
    }
}