old_contents: window['include'] = function() {
  
  	var toLoad = arguments.length;
  	var callback;
  	var hasCallback = arguments[toLoad - 1] instanceof Function;
  	var script;
  
  	function onloaded() {
  		toLoad --;
  		if (!toLoad) {
  			callback();
  		}
  	}
  
  	if (hasCallback) {
  		toLoad --;
  		callback = arguments[arguments.length - 1];
  	} else {
  		callback = function() {}; // noop
  	}
  
  	for (var i = 0; i < toLoad; i ++) {
  
  		script = document.createElement('script');
  		script.src = arguments[i];
  		script.onload = script.onerror = onloaded;
  		(
  			document.head ||
  			document.getElementsByTagName('head')[0]
  		).appendChild(script);
  
  	}
  
  };
  
new_contents: include = function() {
  
  	var args = arguments;
  	var doc = document;
  
  	var toLoad = args.length;
  	var callback;
  	var hasCallback = args[toLoad - 1] instanceof Function;
  	var script;
  
  	function onloaded() {
  		toLoad --;
  		if (!toLoad && callback) {
  			callback();
  		}
  	}
  
  	if (hasCallback) {
  		toLoad --;
  		callback = arguments[arguments.length - 1];
  	}
  
  	for (var i = 0; i < toLoad; i ++) {
  
  		script = doc.createElement('script');
  		script.src = arguments[i];
  		script.onload = script.onerror = onloaded;
  		(
  			doc.head ||
  			doc.getElementsByTagName('head')[0]
  		).appendChild(script);
  
  	}
  
  };
  
subject: Save about 9 bytes when uncompressed