AppendJavascript at the end of the footer Asynchronously.

appendToFooter.php

<?php
global $dev_environment;
//$dev_environment = false;

    ?>

<script type='text/javascript'>
  if((typeof $jQ == 'undefined') || (!$jQ)){
      
function downloadJSAtOnload() {
var htmlLast = document.getElementsByTagName('html')[0].lastChild;    
    
    
var jQueryNew = document.createElement("script");
jQueryNew.src = "ms_includes/jquery-1.11.0.min.js";

var allAjaxTests = document.createElement("script");
allAjaxTests.src = "ms_includes/ajaxtests.js";

var jQueryMigrate = document.createElement('script');
jQueryMigrate.src = "//code.jquery.com/jquery-migrate-1.2.1.min.js";
htmlLast.appendChild(jQueryNew);

<?php if($dev_environment){ ?>
htmlLast.appendChild(allAjaxTests);
htmlLast.appendChild(jQueryMigrate);
<?php } ?>

}
if (window.addEventListener){
window.addEventListener("load", downloadJSAtOnload, false);}
else if (window.attachEvent){
window.attachEvent("onload", downloadJSAtOnload);}
else {window.onload = downloadJSAtOnload;}

      
      
      
  }
  
</script>
    
<?php 



/* var createLibrary = function(library){
  var resource = document.createElement('script'); 
  resource.src = library;
  var script = document.getElementsByTagName('script')[0];
  script.parentNode.insertBefore(resource, script);
  }
  createLibrary("ms_includes/ajaxtests.js");
  var resource = document.createElement('script');
  var script = document.getElementsByTagName('script')[0];
  resource.innerHTML= "$jQ = jQuery.noConflict()";
  script.parentNode.insertBefore(resource, script);
  createLibrary("//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"); */
?>