function inicio(w, h, url) {

	var ancho,alto,w2,h2;
	w2=w/2
	h2=h/2
	ancho=screen.width/2-w2;
	alto=screen.height/2-h2;
	
	 window.open(""+url+"","","width="+w+",height="+h+",left="+ancho+",top="+alto+"");
}