An URL shortener algorithm

gistfile1.js

var codeset = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
var base = codeset.length;

function encode(n) {

 var converted = "";

 while (n > 0) {
   converted = converted + codeset[n%base];
   n = Math.floor(n/base);
 }

 return converted;
}

function decode(converted) {

 var c = 0, ind;

 for (var i = converted.length-1; i >= 0; i--) {
  c += (codeset.indexOf(converted[i])) * Math.pow(base, i);
 }

 return c;
}

console.log("Test #1: ", 125 == decode(encode(125)));