If you're viewing this page in 800x600 mode it won't do anything. But if you go into 640x480 or 1024x768 mode you'll see that just after the page is done loading it jumps over so that it's automatically centered. You can do anything inside this layer as if its a normal HTML page. I've set the layer's width to 400 and then clipped the edges to "0,0,400,300" so that the text would wrap like this is doing right now.