function setCSS(style) {
	var meta;
	for(var i=0; (meta = document.getElementsByTagName("link")[i]); i++) {
		if(meta.getAttribute("rel").indexOf("style") != -1
		&& meta.getAttribute("href")) {
		meta.disabled = true;
		if(meta.getAttribute("href") == style)	meta.disabled = false;
		}
	}
}

function getCSS() {
	var meta;
	for(var i=0; (meta = document.getElementsByTagName("link")[i]); i++) {
		if(meta.getAttribute("rel").indexOf("style") != -1
		&& meta.getAttribute("href")
		&& !meta.disabled) return meta.getAttribute("href");
	}
	return null;
}

function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
		for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function getPrefCSS() {
	var meta;
	for(var i=0; (meta = document.getElementsByTagName("link")[i]); i++) {
		if(meta.getAttribute("rel").indexOf("style") != -1
		&& meta.getAttribute("rel").indexOf("alt") == -1
		&& meta.getAttribute("href")
		) return meta.getAttribute("href");
	}
	return null;
}

window.onload = function(e) {
	var cookie = readCookie("style");
	var style = cookie ? cookie : getPrefCSS();
	setCSS(style);
}

window.onunload = function(e) {
	var style = getCSS();
	createCookie("style", style, 10);
}