// Setup background
var bgImages = new Array(
	"images/nc1.jpg",
	"images/nc2.jpg",
	"images/nc3.jpg",
	"images/nc4.jpg",
	"images/nc5.jpg"
);

// Apply background
jQuery('body').css('background-image', 'url(' + bgImages[Math.round(Math.random()* (bgImages.length - 1))] + ')');