// styleswitcher.js

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);