base37.js

var alpha = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("");

function convert(string){
  var pow = 0;
  var res = 0;
  while(pow < string.length){
    res += (alpha.indexOf(string.split("")[pow]) + 1) * Math.pow(37, pow); 
    pow++;
  }
  return res;
};