【background】
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.11.0.js'></script>
<script type='text/javascript'>
$(window).load(function(){
$("#b").click(function(e){
$("body").css("background-color","yellow");
console.log("background-color has changed successfully");
e.preventDefault();
});
});
</script>
</head>
<body>
<a href="javascript:void(0);" id="b">Click</a>
</body>
</html>
