[Emanuele]

You have to put a relative position on the container and absolute position for images. Code:

@charset "utf-8";
/* CSS Document */

#holder
	{
		position:relative;
		width: 80%;
		height: 5em;
		display: block;
	}

img.tl
	{
		float: left;
		width: 18px;
		height: 18px;
	}

img.tr
	{
		float: right;
		width: 18px;
		height: 18px;
	}

img.bl
	{
	clear: both;
	position:absolute;
	float:left;
	width: 18px;
	height: 18px;
	bottom: 0px;
	left: 0px;

	}

img.br
	{
		float: right;
		position: absolute;
		clear: right;
		width: 18px;
		height: 18px;
		bottom: 0px;
		right: 0px;
	}

Cheers.