// Add a script element as a child of the body
 function downloadJSAtOnload() {
 var element = document.createElement("script");
 element.src = "show_ads.js";
 document.body.appendChild(element);
 }
 // Check for browser support of event handling capability
 if (window.addEventListener)
 window.addEventListener("load", downloadJSAtOnload, false);
 else if (window.attachEvent)
 window.attachEvent("onload", downloadJSAtOnload);
 else window.onload = downloadJSAtOnload;
<script language="JavaScript" src="../css.js"></script>