addEvent(window,'load',inicializarEventos,false);

function inicializarEventos()
{
var loca=window.location;
loca=String(loca);
var loce=loca.split('/');
var n=loce.length;
var siloce=loce[Number(n-1)];
if (siloce=='cuadros.html'|| siloce=='')
{
  var ref=document.getElementById('periodos');
  var vec= ref.getElementsByTagName('img');
  var vec2=ref.getElementsByTagName('a');
  for(f=0;f<vec2.length;f++)
  {
    addEvent(vec[f],'mouseover',entrar,false);
    addEvent(vec[f],'mouseout',salir,false);
    //addEvent(vec2[f],'click',presionBoton,false);
  }
}
}

function entrar(e)
{
  var ref;
  var refi;
  if (window.event)
    ref=window.event.srcElement;
  else
    if (e)
      ref=e.target;
 		refi=ref.id;
      document.getElementById(refi).src='../imagenes/'+refi+'b.png'; 

}

function salir(e)
{
  var ref;
  if (window.event)
    ref=window.event.srcElement;
  else
    if (e)
      ref=e.target;
 		refi=ref.id;
      document.getElementById(refi).src='../imagenes/'+refi+'.png'; 
  
}


//function presionBoton(e)
//{
  //var ref;
  //if (window.event)
  //{
    //window.event.returnValue=false;
    //ref=window.event.srcElement;
	//if (ref.parentNode.getAttribute('href')=='http://www.serviarte.com/index.php' || ref.parentNode.getAttribute('href')=='http://serviarte.com/index.php')
     //{
	  //document.getElementById('pagina').src='zoom.php';
     //}
    //else 
	 //{
	 //document.getElementById('pagina').src=ref.parentNode.getAttribute('href');
	 //}
  //}
  //else
    //if (e)
    //{
      //e.preventDefault();
      //ref=e.target;
	  //if (ref.parentNode.getAttribute('href')=='index.php')
      //{
	   //document.getElementById('pagina').src='zoom.php';
      //}
     //else 
	   //{
	   //document.getElementById('pagina').src=ref.parentNode.getAttribute('href');
	   //}
    //}
//}


//***************************************
//Funciones comunes
//***************************************

function addEvent(elemento,nomevento,funcion,captura)
{
  if (elemento.attachEvent)
  {
    elemento.attachEvent('on'+nomevento,funcion);
    return true;
  }
  else  
    if (elemento.addEventListener)
    {
     elemento.addEventListener(nomevento,funcion,captura);
      return true;
    }
    else
      return false;
}

function crearXMLHttpRequest() 
{
  var xmlHttp=null;
  if (window.ActiveXObject) 
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  else 
    if (window.XMLHttpRequest) 
      xmlHttp = new XMLHttpRequest();
  return xmlHttp;
}