TẮT/MỞ ĐÈN CHO BLOGSPOT/WEBSITE

<style>
/* Turn off the lights
----------------------------------------------- */
#lightsVideo {
position:relative;
z-index:102;
}
#switch {
max-width:640px;
text-align:left;
position:relative;
height:25px;
display:block;
}
.lightSwitcher {
position:absolute;
z-index:101;
background-image:url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitDOELW3C1RuaKeZREVkvxiv6ZRywbPR5_Xgo50rSlbWJLcoFUhXCDZqQYHLmXbGmvPtQrAyJMKGXybt6EV-mOO0wv-PJAvNFGYpepLFa6hFWp0tWjDFoX2lLk-dJda6oJABnerMoubB2A/s1600/lights-on.png);
background-repeat:no-repeat;
background-position:left;
padding: 0 0 0 20px;
outline:none;
text-decoration:none;
}
.lightSwitcher:hover {text-decoration:underline;}
.turnedOff {
color:#ffff00 !important;
background-image:url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLswme1x-0pLzeb1nv4sNPMVR4qLo5PJIx8J0noHs4WM0HNR2BKQ7UzhAkwbmhzT9cDcTf702u54C7m9ZOXlXSQbhk_VQbnIjxeB7B6XeKEg2Lxwp4va6HVZVQXKFpAjJLXbAGhP8MIK7V/s1600/lights-off.png);
}
#lightsoff {
background:#000;
opacity:0.3;
filter:alpha(opacity=90);
position:absolute;
left:0;
top:0;
width:100%;
z-index:0;
}
</style>
<script src='http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js' type='text/javascript'></script>
  <!-- Start tắt/mở đèn -->
<script type='text/javascript'>
//<![CDATA[
$(document).ready(function(){
$("#lightsoff").css("height", $(document).height()).hide();
$(".lightSwitcher").click(function(){
$("#lightsoff").toggle();
if ($("#lightsoff").is(":hidden"))
$(this).html("Tắt đèn").removeClass("turnedOff");
else
$(this).html("Mở đèn").addClass("turnedOff");
});
});
//]]>
</script>
<!-- End tắt/mở đèn -->
<li class='button-effect' id='switch'><a class='lightSwitcher' href='javascript:void(0);'>Tắt đèn</a></li>
đặt trên /body đoạn này
<div id='lightsoff'/>