Load external scripts one by one.

script-loader.js

/**
 * script-loader.js
 * Load external scripts one by one. 
 * (Load certain script after previous script is loaded.)
 */
(function script_loader(scripts) {
   if (scripts.length <= 0) return;
   var uri = scripts.shift();
   var script = document.createElement('script');
   script.type = 'text/javascript';
   script.charset = 'utf-8';
   script.src = uri;
   script.onload = function() { script_loader(scripts); };  // call myself recursively when script is loaded
   script.onreadystatechange = function() {  // IE supports onreadystatechange instead of onload
     if (script.readyState === 'loaded' || script.readyState === 'complete') {
       script.onload(scripts);
       script.onreadystatechange = script.onload = null;
     }
   };
   document.body.appendChild(script);
 })([
      'http://example.com/example1.js',
      'http://example.com/example2.js',
      'http://example.com/example3.js'
    ]);