<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("p").one("click",function(){
$(this).animate({fontSize:"+=6px"});
});
});
</script>
</head>
<body>
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
<p>Click any p element to increase its text size. The event will only trigger once for each p element.</p>
</body>
</html>