function ctrSort(a, b)
{
	return (b.ctr - a.ctr);
}

function generatePreviews(previews, size)
{
	var generated = '';
	previews.sort(ctrSort);
	var s = 0;
	for (var i in previews)
	{
		s += previews[i].ctr;
	}
	var c = 0;
	for (var i in previews)
	{
		if ((previews.length-i == size-c) || (Math.random() <= previews[i].ctr / s * size))
		{
			$.post('update_view/'+previews[i].nid);
			generated += '<div id="preview_' + c + '">' + previews[i].image + '<div class="preview_' + c + '_link">' + previews[i].link + '</div></div>';
			if (++c == size) break;
		}
	}	
	return generated;
}