function setCookie(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+"="+escape(value)+expires+"; path=/;";
};

function getCookie(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 unescape(c.substring(nameEQ.length,c.length));
     }
  }
  return null;
};

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

function setFontSize(size) {
  setActiveStyleSheet('font', size);
  setCookie('font_size', size);
}