var size = 90;

function font_resize(){

  var size_cookie = getCookie('font_size');

	if(size_cookie != null) {
	
	size = parseInt(size_cookie);

	document.body.style.fontSize = size + '%';
	}
}

function setCookie(key, value, days, path, domain, secure) {
  value = encodeURIComponent(value); // hodnota value by měla být minimálně escapována pomocí funkce escape()
  value+='; domain='+domain;
  value+='; path='+path;
  // expirace
  var date = new Date();
  date.setTime(date.getTime() + days * 24 * 60 * 60 * 1000);
  value+='; expires=' + date.toGMTString();
  // secure
  if (secure) value+='; secure';
  document.cookie = key + '=' + value;
  }

  function getCookie(name) {
   var start = document.cookie.indexOf(name+"=");
   var len = start+name.length+1;
   if ((!start) && (name != document.cookie.substring(0,name.length))) return null;
   if (start == -1) return null;
   var end = document.cookie.indexOf(";",len);
   if (end == -1) end = document.cookie.length;
   return unescape(document.cookie.substring(len,end));
}

function incSize(){

	size = size + 10;
	
  document.body.style.fontSize = size + '%';
  setCookie('font_size', size, 30, '/', server, false);
};

function decSize(){
  size = size - 10;
  document.body.style.fontSize = size + '%';
  setCookie('font_size', size, 30, '/', server, false);
};