window.onload = function(){
	numero = parseInt(Math.random() * 2);
	elm = document.getElementsByClassName('logo');
		for(var i = 0; i < elm.length; i++){			
			cero = numero >= 10 ? '' : '0';
			img = 'url(img/cabeceraInt_' + cero + numero + '.png)';
			right = 'right'
			norepeat = 'no-repeat'
			elm[i].style.backgroundImage = img;
			window.setTimeout('cambiaImagen()',30000);
		}	
	}
	
	if(!document.getElementsByClassName){
	document.getElementsByClassName = function(cl) {
		var retnode = [];
		var myclass = new RegExp('\\b'+cl+'\\b');
		var elem = this.getElementsByTagName('*');
		for (var i = 0; i < elem.length; i++) {
			var classes = elem[i].className;
			if (myclass.test(classes)) retnode.push(elem[i]);
		} 
		return retnode;
	}
	
}


function cambiaImagen(){
	numero = parseInt(Math.random() * 2);
	elm = document.getElementsByClassName('logo');
		for(var i = 0; i < elm.length; i++){			
			cero = numero >= 10 ? '' : '0';
			img = 'url(img/cabeceraInt_' + cero + numero + '.png)';
			right = 'right'
			norepeat = 'no-repeat'
			elm[i].style.backgroundImage = img;
			window.setTimeout('cambiaImagen()',30000);
		}	
	}
	
	if(!document.getElementsByClassName){
	document.getElementsByClassName = function(cl) {
		var retnode = [];
		var myclass = new RegExp('\\b'+cl+'\\b');
		var elem = this.getElementsByTagName('*');
		for (var i = 0; i < elem.length; i++) {
			var classes = elem[i].className;
			if (myclass.test(classes)) retnode.push(elem[i]);
		} 
		return retnode;
	}
	
}