function determineInclude(buildDir)
	{
	//---- Set this variable only! ----
	// var buildDir = "includes/";
	//---------------------------------

	var ie4 = false, ie5_mac = false, ie55 = false;
	var nn4 = false, dom = false, opera = false, safari = false;
	var agent = navigator.userAgent.toLowerCase();

	if (agent.indexOf("opera") != -1)
		opera = true;
	else if (agent.indexOf("safari") != -1)
		safari = true;
	else if (document.all)
	{
		var version = parseFloat(agent.substr(agent.indexOf("msie")+5, 3));
		if (agent.indexOf("mac") != -1 && version >= 5)
			ie5_mac = true;
		else
		{
			if (version >= 5.5)
		dom = true;
			else if (version >= 4)
				ie4 = true;
		}
	}
	//else if (document.layers)
	else if (navigator.appName == "Netscape" && parseInt(navigator.appVersion) >= 4 && 
		parseInt(navigator.appVersion) < 5)
		nn4 = true;
	else if (document.getElementById)
		dom = true;

	var blank = new Image();
	blank.src = buildDir + "blank.gif";

	if (ie4)
		document.write('<script type="text/javascript" src="' + buildDir + 'ie4-build.js"></script>');
	else if (ie5_mac)
		document.write('<script type="text/javascript" src="' + buildDir + 'ie5m-build.js"></script>');
	else if (ie55)
		document.write('<script type="text/javascript" src="' + buildDir + 'ie55-build.js"></script>');
	else if (nn4)
		document.write('<script type="text/javascript" src="' + buildDir + 'ns4-build.js"></script>');
	else if (dom)
		document.write('<script type="text/javascript" src="' + buildDir + 'dom-build.js"></script>');
	else if (opera)
		document.write('<script type="text/javascript" src="' + buildDir + 'op7-build.js"></script>');
	else if (safari)
		document.write('<script type="text/javascript" src="' + buildDir + 'saf-build.js"></script>');
	else
	{
		alert("Your browser doesn't support this script.");
		location.href = buildDir + "upgrade.html";
		document.write('<script type="text/javascript" src="' + buildDir + 'no-build.js"></script>');
	}
	
	return buildDir;
}