function clip_img_fixe(id, dim) {
	var img = document.getElementById(id);

	if( img.naturalHeight ) { 
		//firefox
		h = img.naturalHeight;
		w = img.naturalWidth;
	} else {
		//IE
		lgi = new Image();
		lgi.src = img.src;
		h = lgi.height;
		w = lgi.width
	}
	new_w = dim;
	new_h = Math.round(dim * h /w);
	t = - Math.round((new_h-dim)/2);
	l = 0;

	img.style.width = new_w + "px";
	img.style.height = new_h + "px";
	img.style.top = t + "px";
	img.style.left = l + "px";
}