function popup(filename,windowname,w,h) {
					var xw = w;	var xh = h;
					if(screen) { var xxw = (screen.width-xw)/2; var xxh = (screen.height-xh)/2 }
					else { var xxw = 80; var xxh = 80; }

					var newwin = open(filename, windowname,'scrollbars=yes,status=no,menubar=no,directories=no,resize=no,width=' +w +',height=' + h + ',top=' + xxh + ',left=' + xxw );
				}
				
function OpenWin(theURL,winName,width,height) { 
	if(window.screen){
		per_ancho=(width/800)*100;//porcentaje screen-ancho
		per_alto=(height/width)*100;//porcentaje de ancho-alto
		win_ancho=(screen.width*per_ancho)/100;//ancho de la ventana
		win_alto=(win_ancho*per_alto)/100;//alto de la ventana
		x=(screen.width-win_ancho)/2;//centra x
		y=(screen.height-win_alto)/2;//centra y
	}else{// si el buscador es 4-- queda todo igual :(
		x=0;
		y=0;
		win_ancho=w;
		win_alto=y;
	}
	features=("top="+y+",left="+x+",width="+win_ancho+",height="+win_alto+",resizable=yes,scrollbars=yes");
	promo=window.open(theURL,winName,features);
	promo.focus();
}