$(document).ready(function() { 
	var sloganArray = ['slogan1.jpg', 'slogan2.jpg', 'slogan3.jpg', 'verkoopofkoop.png'];
	var randomnumber=(Math.round(Math.random()*3));
	sloganURL = 'url(\'images/' + sloganArray[randomnumber] + '\')';
	$('div#subheader').css('background', sloganURL);
});