$(document).ready(function() {
	var randomImages = ['img1','img2','img3','img4','img5','img6','img8'];
	var rndNum = Math.floor(Math.random() * randomImages.length);
	$("div.feature_img").css({ background: "url(images/" + randomImages[rndNum] + ".jpg) 100% 100% no-repeat" });
});