function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document.images[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		menu_01_over = newImage("images/menu_01-over.gif");
		menu_02_over = newImage("images/menu_02-over.gif");
		menu_02_menu_03_over = newImage("images/menu_02-menu_03_over.gif");
		menu_03_over = newImage("images/menu_03-over.gif");
		menu_04_over = newImage("images/menu_04-over.gif");
		menu_05_over = newImage("images/menu_05-over.gif");
		preloadFlag = true;
	}
}

function mostrarempresa(anterior){
	var imagenes = new Array("foto1","foto2","foto3","foto4");
	
	function enlaceAleatorio(){ 
	    aleat = Math.random() * imagenes.length;
	    aleat = Math.floor(aleat);
	    return aleat;
	}
	num_aleatorio = enlaceAleatorio();
	
	
	
	switch(imagenes[num_aleatorio]){
		case "foto1":
			html = "<img src='images/cabecera2.jpg' border='0' alt='Yo Miranda' usemap='#Map2'>"
			break;
		case "foto2":
			html = "<img src='images/cabecera3.jpg' border='0' alt='Yo Miranda' usemap='#Map2'>"
			break;
		case "foto3":
			html = "<img src='images/cabecera4.jpg' border='0' alt='Yo Miranda' usemap='#Map2'>"
			break;
		case "foto4":
			html = "<img src='images/cabecera5.jpg' border='0' alt='Yo Miranda' usemap='#Map2'>"
			break;
	
	}
	
	document.write(html);
	return num_aleatorio;
}