window.History
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>History对象</title>
</head>
<script type="text/javascript">
var HL = window.history.length//back(),forward(),go();
document.write(HL);
</script>
<body>
</body>
</html>
