var styleCookie = getCookie("style");
if (styleCookie)
  swapStyle(styleCookie, true);

function swapStyle(style, dontWrite) {
  if (!dontWrite) setCookie("style", style, 30);

  var styleSheets = document.styleSheets;
  for (var i = 0; i < styleSheets.length; i++) {
    var title = styleSheets[i].title;
    if (title) {
      if (title == style)
        styleSheets[i].disabled = false;
      else
        styleSheets[i].disabled = true;
    }    
  }
  return false;
}

function setCookie(name, value, days) {
  var expireDate = new Date();
  expireDate.setTime(expireDate.getTime() + (days * 24 * 3600 * 1000));

  document.cookie = name + "=" + escape(value) + "; expires=" + expireDate.toGMTString();
}

function getCookie(name) {
  if (document.cookie.length > 0) {
    var start;
    var end;

    start = document.cookie.indexOf(name + "=");
    if (start == -1) return null;
    end = document.cookie.indexOf(";", start);
    if (end == -1) end = document.cookie.length;

    return unescape(document.cookie.substring(start + name.length + 1, end));
  }
  return null;
}