setInterval(function() {
				var $ran = Math.ceil(Math.random()*2);	// la multiplicaci—n determina la cantidad de imagenes.
				var $valor = "url(<?php echo base_url()?>www/views/media/images/cabecera"+$ran+".jpg)";
			$('.Cabecera').css({ background: $valor });
			}, 3000);	

			
			
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			  _gaq.push(['_setAccount', 'UA-26407123-1']);
			  _gaq.push(['_trackPageview']);
			
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			    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
			    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
			    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
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