var ua = navigator.userAgent;
if (ua.indexOf("MSIE") >= 0 && document.execCommand) {
  document.execCommand("BackgroundImageCache", false, true);
}

var cookie = {};

cookie.get = function(name) {
    var regexp = new RegExp('; ' + name + '=(.*?);');
    var match  = ('; ' + document.cookie + ';').match(regexp);
    return match ? decodeURIComponent(match[1]) : '';
}

cookie.set = function(name, value) {
    var buf = name + '=' + encodeURIComponent(value);
    document.cookie = buf + '; path=/; expires=Mon, 31-Dec-2029 23:59:59 GMT';
}

function char_size(n) {
 var size = cookie.get('fsize');
 if (!size) size = 80;
 size -= 0;

 if (n == 'c') ;
 else if (n == 0) size = 80;
 else if (n > 0 && size < 300) size += n;
 else if (n < 0 && 40 < size) size += n;

 var el = document.getElementById('wrapper');
 el.style.fontSize = size + '%';
 cookie.set('fsize', size);
}