$(document).ready(function() { var randomImages = ['banner_01','banner_02','banner_03','banner_04','banner_05','banner_06','banner_07']; var rndNum = Math.floor(Math.random() * randomImages.length); $("div#banner").css({ background: "url(http://www.kids-of-africa.com/files/images/banner-home/" + randomImages[rndNum] + ".jpg) no-repeat" }); });