【mouse】
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-2.1.0.js'></script>
<script type='text/javascript'>
$(window).load(function(){
$('.a').on('mouseenter', function(e){
$('.b').css('color','red')
});
$('.a').on('mouseleave', function(e){
$('.b').css('color','black')
});
});
</script>
</head>
<body>
<div class="a">Hover here</div>
<br>
<div class="b">Something else</div>
</body>
</html>
