<html>
<body>
<textarea id="myText" cols="70" rows="2" onclick="function1(this);">
Sample text for the document
</textarea>
<button onclick="function1()">Bounding Height</button>
<script language="JavaScript"> function function1() {
var m = myText.createTextRange();
alert(m.boundingHeight);
}
</script>
</body>
</html>