execute a script that has been preloaded already
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();
			}
		}