Determing JavaScript version for a browser

By combining HTML and javascript together we can set up a Javascript variable containing the version number as follows:

<script type="text/javascript">
var jsver = 1.0;
</script>

<script language="Javascript1.1">
jsver = 1.1;
</script>

<script language="Javascript1.2">
jsver = 1.2;
</script>

<script language="Javascript1.3">
jsver = 1.3;
</script>

<script language="Javascript1.4">
jsver = 1.4;
</script>

<script language="Javascript1.5">
jsver = 1.5;
</script>

<script language="Javascript1.6">
jsver = 1.6;
</script>

<script type="text/javascript">
document.write('<p><b>Javascript version ' + jsver + ' supported by your browser.<\/b><\/p>');
</script>