function toggle(foo) {
	if (document.getElementById(foo).style.display == "none") {
		show(foo);
	} else {
		if (document.getElementById(foo).style.display == "block") {
			hide(foo);
		} else {
			show(foo);
		}
	}
}

function show(foo) {
	document.getElementById(foo).style.display = "block";
	setCookie(foo, "o",null,"/");
}

function hide(foo) {
	document.getElementById(foo).style.display = "none";
	setCookie(foo, "c",null,"/");
}

function setMenuState(id) {
	status = getCookie(id);
	if (status=="o") {
		show(id);
	} else if (status=="c") {
		hide(id);
	}
}

// name - name of the cookie
// value - value of the cookie
// [expires] - expiration date of the cookie (defaults to end of current session)
// [path] - path for which the cookie is valid (defaults to path of calling document)
// [domain] - domain for which the cookie is valid (defaults to domain of calling document)
// [secure] - Boolean value indicating if the cookie transmission requires a secure transmission
// * an argument defaults when it is assigned null as a placeholder
// * a null placeholder is not required for trailing omitted arguments
function setCookie(name, value, expires, path, domain, secure) {
	var curCookie = name + "=" + escape(value) + ((expires) ? "; expires="
		+ expires.toGMTString() : "")
		+ ((path) ? "; path=" + path : "") + ((domain) ? "; domain=" + domain : "")
		+ ((secure) ? "; secure" : "");
	document.cookie = curCookie;
}

// name - name of the desired cookie
// * return string containing value of specified cookie or null if cookie does not exist
function getCookie(name) {
	var dc = document.cookie;
	var prefix = name + "=";
	var begin = dc.indexOf("; " + prefix);
	if (begin == -1) {
		begin = dc.indexOf(prefix);
		if (begin != 0) return null;
	} else begin += 2;
	var end = document.cookie.indexOf(";", begin);
	if (end == -1) end = dc.length;
	return unescape(dc.substring(begin + prefix.length, end));
}

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);