<!DOCTYPE html>
<html>
<head>
<script src="https://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script>
<script>
$(document).ready(function(){ $("#btn1").click(function(){ $("div").height(500); });
$("#btn2").click(function(){ $("div").height("10em"); });
$("#btn3").click(function(){ $("div").height("200pt"); });
});
</script>
</head>
<body>
<button id="btn1">Set height of div to 500px</button>
<button id="btn2">Set height of div to 10em</button>
<button id="btn3">Set height of div to 200pt</button>
<p><b>Note:</b> Use "" for em, pt, etc.</p>
<div style="height:100px;border:1px solid blue;background-color:lightblue;"></div><br>
</body>
</html>