var px = {'small':'10', 'middle':'12', 'large':'14'};
var cookie = ' ' + document.cookie +';';
var key = 'size=';
var i = cookie.indexOf(key);
var size;

if (i != -1){ i += key.length;size = unescape(cookie.substring(i, cookie.indexOf(';', i))); }
if (!px[size]){ size = 'middle'; }

document.write('<style type="text/css">body { font-size:'+ px[size] +'px; }</style>');

function font_size(size){ 
	document.body.style.fontSize = px[size] +'px';
	document.cookie = key + size +';expires=Tue, 1-Jan-2030 00:00:00 GMT;path=/;';
}