<!DOCTYPE html>
<html>
<head>
<title>jQuery :hidden Selector</title>
<script src="jquery-latest.min.js"></script>
<script>
$(document).ready(function() {
$("p:hidden").slideDown(5000);
});
</script>
<style>
.param {
display: none;
color: red;
}
</style>
</head>
<body>
<h1>Article heading</h1>
<p>first paragraph</p>
<p class="param">second paragraph</p>
<p>third paragraph</p>
</body>
</html>