Script loader without having to wrap code?

Question

If I understand what you are meaning, you want to load a separate JavaScript file after the page is loaded. I have an example that shows how you can have a module spread over multiple files and load additional pieces of that module at later calls. First, a great summary of different module patterns can be found here: Adequately Good: Module Patterns and a very nice code snippet that shows a JavaScript loader can be found here: Loading JS files Asynchronously

My Module's name is myModule and it gets three functions during the initial load: addNumbers(), doOperations(), and difNumbers(). Then after the document is loaded, we store in tmp the answer to doOperations(). After that, we want to load the multiply.js script so that myModule has the multNumbers() function, so we call loadScript() with the URL to the file, and give it a callback that will print the multiplication to the console.

Here is my code:

HTML File

<html>
   <head>
      <title>Module Pattern</title>
      <meta charset="UTF-8">
      <script>
         var myModule = (function(my) {
            my.addNumbers = function(a, b) {
               return a + b;
            };
            return my;
         }(myModule || {}));
      </script>
      <script>
         var myModule = (function(my) {
            my.doOperations = function(a, b) {
               return{
                  c: my.addNumbers(a, b),
                  d: my.difNumbers(a, b)
               };
            };
            return my;
         }(myModule || {}));
      </script>
      <script>
         var myModule = (function(my) {
            my.difNumbers = function(a, b) {
               return a - b;
            };
            return my;
         }(myModule || {}));
      </script>
      <script>
         function loadScript(url, success) {
            var script = document.createElement("script");
            script.src = url;
            var head = document.getElementsByTagName("head")[0],
                    done = false;
            script.onload = script.onreadystatechange = function() {
               if (!done && (!this.readyState ||
                       this.readyState === "loaded" ||
                       this.readyState === "complete")) {
                  done = true;
                  success();
                  script.onload = script.onreadystatechange = null;
                  head.removeChild(script);
               }
            };
            head.appendChild(script);
         }
      </script>
      <script>
         function main() {
            var tmp = myModule.doOperations(5, 6);

            loadScript("multiply.js", function() {
               console.log(myModule.multNumbers(7, 9));
            });
            console.log(tmp.c);
            console.log(tmp.d);
         }
      </script>
   </head>
   <body onload="main();">
      <div>I do operations</div>
   </body>
</html>

multiply.js

var myModule = (function(my) {
   my.multNumbers = function(a, b) {
      return a * b;
   };
   return my;
}(myModule || {}));