// JavaScript Document
var CSS_FOLDER = "bg_css";

function csswechsel(cssname) {
	var css = document.getElementsByTagName("link");
	for (var i=0; i < css.length; i++) {
		if (css[i].getAttribute("title") != "extra") continue;
		css[i].setAttribute("href", cssname);
	}
	document.cookie = "css="+ cssname +"; path=/";
}

function cssbehalten() {
	var css = CSS_FOLDER+"/bg0.css";
	var cookies = document.cookie.split(";"); 
	for (var i=0; i < cookies.length; i++) {
		var cookie = cookies[0].replace(/^ +/, "");
		if (cookie.indexOf("css=") != 0) continue;
		css = cookie.substring(4);
		break; 
	}  
	csswechsel(css);
}

function csslink(el) {
  var img = el.getElementsByTagName("img")[0];
  var imgname = img.src.substr(img.src.lastIndexOf("/")+1);
  var cssname = imgname.substr(0, imgname.lastIndexOf(".")) +".css";
  csswechsel(CSS_FOLDER+"/"+cssname);
}
cssbehalten();