Use the following JavaScript to determine which .NET version is on a client PC:
<script language="JavaScript" type="text/javascript">
var a = navigator.userAgent.match(/\.NET CLR [0-9.]+/g);
if (a == null)
document.write( ".NET Framework(s) is not installed" )
else
{
document.write
( "The following versions of .NET Frameworks are installed:<br/>" )
for (i = 0; i < a.length; ++i)
{
document.write( a[i] )
document.write( "<br/>" )
}
}
</script>
