Open up templates/subsilver/subsilver.css and put in there
#shoutbox {
	position:absolute;
	width:121px;
	height:201px;
	z-index:1;
	left: 556px;
	top: 581px;
}
Close and save that now open index.php and put in there
<div id="shoutbox"><?php include('shoutboxfile.php'); ?></div>

Close and save that your done.