var currentsize = 'medium';

function decrease() {
var newsize;
switch (currentsize) {
		case 'x-small': newsize = 'xx-small'; break;
   		case 'small': newsize = 'x-small'; break;
		case 'medium': newsize = 'small'; break;
		case 'large': newsize = 'medium'; break;
		case 'x-large': newsize = 'large'; break;
		case 'xx-large': newsize = 'x-large'; break;
		default: newsize = 'xx-small'; break;
	}
	document.getElementById('menu').style.fontSize = newsize;
	document.getElementById('content').style.fontSize = newsize;
	currentsize = newsize;
	}
	
function increase() {
var newsize;
switch (currentsize) {
		case 'xx-small': newsize = 'x-small'; break;
		case 'x-small': newsize = 'small'; break;
   		case 'small': newsize = 'medium'; break;
		case 'medium': newsize = 'large'; break;
		case 'large': newsize = 'x-large'; break;
		default: newsize = 'x-large'; break;
	}
	document.getElementById('menu').style.fontSize = newsize;
	document.getElementById('content').style.fontSize = newsize;
	currentsize = newsize;
	}	
	
	
<!--
function getPreferredStyleSheet() {
  
}


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("fontsize");
  var title = cookie ? cookie : getPreferredStyleSheet();
  currentsize = title; 
//	currentstatus();
}

window.onunload = function(e) {
  var title = currentsize;
  createCookie("fontsize", title, 365);
  //currentstatus();
}

function currentstatus() {
document.getElementById("menu").style.fontSize = currentsize;
document.getElementById("content").style.fontSize = currentsize;
}	

var cookie = readCookie("fontsize");
var title = cookie ? cookie : getPreferredStyleSheet();
currentsize = title; 

// -->