Untitled

<body>
<h1>localStorage window broadcast example</h1>
<script>

function openwindows(n){
    var h = window.screen.height / n,
        w = window.screen.width / n, i, j;

    for (i = 0; i < n; i += 1) {
        for (j = 0; j < n; j += 1) {
            window.open('window.html', '_blank', "width=" + (w - 10) +  ",height=" + (h - 60) + ",resizable=no,scrollbars=no,status=no,left=" + (i * w) + ",top=" + (j * h));
        }
    }
}

function openwindow(){
    var h = window.screen.height,
        w = window.screen.width;

    window.open('window.html', '_blank', "width=200,height=200,resizable=no,scrollbars=no,status=no,left=" + (~~(Math.random()*w)) + ",top=" + (~~(Math.random()*h)));
}

</script>
<button onclick="openwindow();">Open 1 window</button>
<button onclick="openwindows(4);">Open 16 windows</button>
<button onclick="openwindows(5);">Open 25 windows</button>
</body>