function setActiveStyleSheet(title) {
        var i, a, main;
        for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
                if(a.getAttribute("rel").indexOf("style") != -1 &&
                         a.getAttribute("title")) {
                        a.disabled = true;
                        if(a.getAttribute("title") ==title) a.disabled = false;
                }
        }
}

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

function getPreferredStyleSheet() {
        var i, a;
        for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
                if(a.getAttribute("rel").indexOf("style") != -1
                        && a.getAttribute("rel").indexOf("alt") == -1
                        && a.getAttribute("title")
                        ) return a.getAttribute("title");
        }
        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;
}

window.onload = function(e) {
        var cookie = readCookie("style");
        var title = cookie ? cookie : getPreferredStyleSheet();
        setActiveStyleSheet(title);
}

window.onunload = function(e) {
        var title = getActiveStyleSheet();
        createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);