function _linea(ali, ancho, alto, color) {
	var l 	 = "<table margin=0 cellpadding=0 cellspacing=0 align=" + ali;
	l	+= " width=" + ancho + " height=" + alto + " style=background-color:" + color + " >";
	l	+= "<tr><td width=100% height=" + alto + " >";
	l	+= "</td></tr></table>";
	return l;
}