function volver() {
  var historia = ""
      historia = history.go(-1)
  return historia;
}

function cerrar() {
window.close()
}


function _texto_mes() {
	var meses = new Array("Enero", "Febrero", "Marzo", "Abril", "Mayo", "Junio", "Julio", "Agosto", "Septiembre", "Octubre", "Noviembre", "Diciembre");
	return meses[this.getMonth()];}

function _texto_dia() {
	var dias= new Array("Domingo", "Lunes", "Martes", "Miércoles", "Jueves", "Viernes", "Sábado");
	return dias[this.getDay()];}

function fecha() {
	Date.prototype.texto_mes = _texto_mes;
	Date.prototype.texto_dia = _texto_dia;

	var d = new Date();
	d.setTime (d.getTime());

	var dia = ""+d.getDate()
	var largo = dia.length-1
	document.write('<font face="Arial">');
	document.write(d.texto_dia()+' ');

	for (var posicion = 0;posicion<=largo;posicion++) {
	document.write(dia.charAt(posicion));
	}

	document.write(' de ');
	document.write(d.texto_mes());
	document.write(' de ');

	var ano = d.getYear();
	if (ano < 2000) {
	var ano = "19"+ano
	} else {
	var ano = ""+ano
	}

	for (var posicion = 0;posicion<=3;posicion++) {
	document.write(ano.charAt(posicion));
	}	
}

function openWindow(url){
  popupWin = window.open(url, "targetwin", "menubar,toolbar,scrollbars,width=750,height=550");
}

function buildArray() {
  var a = buildArray.arguments;
  for (i=0; i<a.length; i++) {
    this[i] = a[i];
  }
  this.length = a.length;
}

function go(which, num, win) {
  var urls1 = new buildArray("",
  "liniers.htm",
  "eduypsic.htm",
  "informat.htm",
  "musica.htm",
  "varios.htm",
  "mensajes.htm");
  n = which.selectedIndex;
  if (n != 0) {
    var url = eval("urls" + num + "[n]")
    if (win) {
      openWindow(url);
    } else {
      location.href = url;
    }
  }
}