JavaScript 实现网页自动锁定与密码解锁功能

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript实现系统屏幕保护效果(锁定网页)</title>
</head>

<body>
<div id="dvContent">内容<br />内容<br />内容<br />内容<br />内容<br />内容</div>
<div id="dvPassword" style="display:none">输入密码：<input type="password" id="txtPwd" /><input type="button" value="确定" onclick="check()"/></div>
<script>
  if (document.cookie.indexOf('lock=1') != -1) ShowContent(false);
  var delay = 10 * 1000,timer;//10s后锁定，修改delay为你需要的时间，单位毫秒
  function startTimer() {
    clearTimeout(timer);
    timer = setTimeout(TimerHandler, delay);
  }
  function TimerHandler() {
    document.cookie = 'lock=1';
    document.onmousemove = null;//锁定后移除鼠标移动事件
    ShowContent(false);
  }
  function ShowContent(show) {
    document.getElementById('dvContent').style.display = show ? 'block' : 'none';
    document.getElementById('dvPassword').style.display = show ? 'none' : 'block';
  }
  function check() {
    if (document.getElementById('txtPwd').value == '123') {
      document.cookie = 'lock=0';
      ShowContent(true);
      startTimer()//重新计时
      document.onmousemove = startTimer; //重新绑定鼠标移动事件
    }
    else alert('密码不正确！！');
  }
  window.onload = function () {
    document.onmousemove = startTimer;
    startTimer();
  }
</script>
</body>
</html>