code: function execute_preloaded_script(chain_opts,script_obj,registry_item) {
  			var script;
  
  			function preload_execute_finished() {
  				if (script != null) { // make sure this only ever fires once
  					script = null;
  					script_executed(registry_item);
  				}
  			}
  
  			if (registry[script_obj.src].finished) return;
  			if (!chain_opts[_AllowDuplicates]) registry[script_obj.src].finished = true;
  
  			script = registry_item.elem || document.createElement("script");
  			if (script_obj.type) script.type = script_obj.type;
  			if (script_obj.charset) script.charset = script_obj.charset;
  			if (script_obj.crossOrigin) script.crossOrigin = script_obj.crossOrigin;
  			create_script_load_listener(script,registry_item,"finished",preload_execute_finished);
  
  			// script elem was real-preloaded
  			if (registry_item.elem) {
  				registry_item.elem = null;
  			}
  			// script was XHR preloaded
  			else if (registry_item.text) {
  				script.onload = script.onreadystatechange = null;	// script injection doesn't fire these events
  				script.text = registry_item.text;
  			}
  			// script was cache-preloaded
  			else {
  				script.src = script_obj.real_src;
  			}
  			append_to.insertBefore(script,append_to.firstChild);
  
  			// manually fire execution callback for injected scripts, since events don't fire
  			if (registry_item.text) {
  				preload_execute_finished();
  			}
  		}
docs: execute a script that has been preloaded already