code: function vers_compare(a, b) {
    a = a.split('.');
    b = b.split('.');
    for (var i = 0; i < 3; i++) {
      var d = parseInt(a[i] || '0') - parseInt(b[i] || '0');
      if (d != 0) {
        return d;
      }
    }
    return 0; // Equal
  }
docs: Compares a vs b, returns < 0 if a < b, > 0 if b > b, 0 if a == b