$(document).ready(function(){
//your code here
$('#reveal').click(function() {
$("#block").fadeIn(1000).fadeOut(1000);
});
});
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css" />
<script src="script.js"></script>
</head>
<body>
<div id="reveal">reveal</div>
<div id = "block"></div>
</body>
</html>
#reveal{
width: 50px;
height: 50px;
background-color: red;
}
#block{
width: 50px;
height: 50px;
background-color: blue;
display:none;
}