msusur/a.js

## a.js
var x = function () {
  alert("working");
};

## b.js
(function () {
  x();
})();

## not-working.html
<html>
  <head>
   <script src="b.js" ></script> <!-- B -->
   <script src="a.js" ></script> <!-- A -->
  </head>
</html>

## working.html
<html>
    <head>
       <script src="a.js" ></script> <!-- A -->
       <script src="b.js" ></script> <!-- B -->
    </head>
</html>
	<html>
	<head>
	<script src="b.js" ></script> <!-- B -->
	<script src="a.js" ></script> <!-- A -->
	</head>
	</html>