Using Multiple Versions of JavaScript with the language Attribute
<html>
<head>
<title>JavaScript version test page</title>
</head>
<body>
<script language="JavaScript">
//Only JavaScript 1.0 browsers read in this section document.write('This browser supports JavaScript 1.0<br>');
</script>
<script language="JavaScript1.1">
//Only JavaScript 1.1 browsers read in this section
document.write('This browser supports JavaScript 1.1<br>');
</script>
<script language="JavaScript1.2">
//Only JavaScript 1.2 browsers read in this section
document.write('This browser supports JavaScript 1.2<br>');
</script>
<script language="JavaScript1.3">
//Only JavaScript 1.3 browsers read in this section
document.write('This browser supports JavaScript 1.3<br>');
</script>
<script language="JavaScript1.4">
//Only JavaScript 1.4 browsers read in this section
document.write('This browser supports JavaScript 1.4<br>');
</script>
<script language="JavaScript1.5">
//Only JavaScript 1.5 browsers read in this section
document.write('This browser supports JavaScript 1.5<br>');
</script>
</body>
</html>