<script>
// see http://www.CodeDesignPatterns.com/javascript/window-onload-function-chaining/
function onloadFunction(prevOnloadFunction) {
   return function() {
      <#before previous window.onload function>
      if (prevOnloadFunction) prevOnloadFunction();
      <#after previous window.onload function>
   };
}
window.onload = onloadFunction(window.onload);
</script>