// variable
var _tag = '<link rel="stylesheet" type="text/css" href="';
// css files housing directory
var _dir = 'css/';

// convert all characters of userAgent to lowercase to simplify testing
var _agent = navigator.userAgent.toLowerCase();

// os variable
var _win = (_agent.indexOf('win') != -1) ? 1 : 0; // Windows
var _mac = (_agent.indexOf('mac') != -1) ? 1 : 0; // Macintosh

// browser variable
// Document Object Model
var _dom  = (document.getElementById) ? 1 : 0;
// iCab (mac only) # as Gecko
var _icab = (_agent.indexOf('icab') != -1) ? 1 : 0;
// Internet Explorer 4.x
var _ie4  = (!_icab && document.all) ? 1 : 0;
// Internet Explorer 5.x or greater
var _ie5  = (_ie4 && _dom) ? 1 : 0;
// Internet Explorer 4.x or 5.x or greater
var _ie   = (_ie4 || _ie5) ? 1 : 0;
// Netscape 6.x (Gecko) or greater or Opera 6.x or iCab
var _gc   = (!_ie && _dom) ? 1 : 0;
// Netscape 4.x
var _ns   = (document.layers) ? 1 : 0;

// os divergence
var _os = (_win) ? 'win' : (_mac) ? 'mac' : 0;

// browser divergence
var _ua = (_gc) ? '_nn6' : (_ie) ? '_ie' : (_ns) ? '_nn4' : '_ie';

// title attribute of stylesheet
var _st  = _os + _ua ;

// css divergence link element description for several environments
if (_ns || (_mac && _ie4)) {
	with (document) {
		open();
		writeln(_tag + _dir + _os + _ua + '.css' +  '" />');
		close();
	}
}
else {
	with (document) {
		open();
		writeln('<style type="text/css">');
		writeln('<!--');
		writeln('@import url("' + _dir + _os + _ua + '.css");');
		writeln('-->');
		writeln('<' + '/style>');
		close();
	}
}
//alert(_os + _ua);