Su IE non so (uso linux, quindi non ho modo di verificare) ma su Chrome e Firefox funziona...
codice:
<!doctype html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=iso-8859-1" />
<meta http-equiv="Content-Language" content="it" />
<title>Esempio per il Forum di HTML.it</title>
<script type="text/javascript">
function open_win(url_add) {
var nWinWidth = 550, nWinHeight = 250, nWinLeft = Math.floor((screen.width - nWinWidth) / 2), nWinTop = Math.floor((screen.height - nWinHeight) / 2);
window.open(url_add, "welcome", "width=" + nWinWidth + ",height=" + nWinHeight + ",top=" + nWinTop + ",left=" + nWinLeft + ",menubar=no,status=no,location=no,toolbar=no,scrollbars=no");
}
</script>
</head>
<body>
<span onclick="open_win('http://www.google.it');" style="cursor:pointer;text-decoration:underline;color:#0000ff;">Clicca qui</span></p>
</body>
</html>