JavaScript Tutorial/MS JScript/mac
@_mac
The @_mac variable determines if an Apple Macintosh system is being used. When the variable is not true, it is defined as NaN.
<html>
<script language="JScript">
<!--
@if (@_mac)
alert("You are using an Apple Macintosh system.");
@else
alert("You are NOT using an Apple Macintosh system.");
@end
-->
</script>
</html>