Código para entradas aleatorias con javascript en blogger

<script type='text/javascript'>
//<![CDATA[
function showLucky(root){
var feed = root.feed;
var entries = feed.entry || [];
var entry = feed.entry[0];
for (var j = 0; j < entry.link.length; ++j) {
if (entry.link[j].rel == "alternate") {
window.location = entry.link[j].href;
}
}
}
function fetchLuck(luck){
script = document.createElement('script');
script.src = '/feeds/posts/summary?start-index='+luck+'&max-results=1&alt=json-in-script&callback=showLucky';
script.type = 'text/javascript';
document.getElementsByTagName('head')[0].appendChild(script);
}
function readLucky(root){
var feed = root.feed;
var total = parseInt(feed.openSearch$totalResults.$t,10);
var luckyNumber = Math.floor(Math.random()*total);
luckyNumber++;
fetchLuck(luckyNumber);
}
function feelingLucky(){
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = '/feeds/posts/summary?max-results=0&alt=json-in-script&callback=readLucky';
document.getElementsByTagName('head')[0].appendChild(script);
}
//]]>
</script>
<div id="myLuckyPost"><a href="#random" onclick="feelingLucky()" title="Entrada al azar">Entrada al azar</a></div>