function cambioImagen(id1, id2, id3)
   {
   
   $('boton_Ch2').style.display='none';
   $('boton_Ch1').style.display='block';

	if(document.getElementById(id1))
	 {
		dataLayer1=document.getElementById(id1);
		dataLayer2=document.getElementById(id2);
		dataLayer3=document.getElementById(id3);

		 dataLayer3.className='novisible';
		 $(id3).setOpacity(0); 
				
		if(dataLayer1.className=='visible') 
		 {
		 //dataLayer.setOpacity(0);  document.getElementById('fotoAtras').className='visible';
 	      new Effect.Opacity(dataLayer2,{duration:1.2,from:0.1,to:1.0, beforeStart:function()
		  {
		  new Effect.Opacity(dataLayer1,{duration:1.1,from:1,to:0.0, afterFinish:function(){
		    dataLayer1.className='novisible'; }
		  
		  });
		  }
		  });
		  dataLayer2.className='visible';


	     }
	    else 
	     {
          
 	      new Effect.Opacity(dataLayer1,{duration:1.2,from:0.1,to:1.0, beforeStart:function()
		  {
		  new Effect.Opacity(dataLayer2,{duration:1.1,from:1,to:0.0, afterFinish:function(){
		    dataLayer2.className='novisible'; }
		  
		  });
		  }
		  });
	  
		   dataLayer1.className='visible';
		 // alert ('ya'); 		

	    }
	 
	 
	 }
	
	return false;
   }
   
   
   
 function cambioImagen2(id1, id2, id3)
   {
   
		dataLayer1=document.getElementById(id1);
		dataLayer2=document.getElementById(id2);
		dataLayer3=document.getElementById(id3);

 	    if(dataLayer1.className=='visible')
		 {
          dataLayer2.className='novisible';
		  $(id2).setOpacity(0); 

		new Effect.Opacity(dataLayer3,{duration:1.2,from:0.1,to:0.95, beforeStart:function()
		  {
		  new Effect.Opacity(dataLayer1,{duration:1.1,from:1,to:0.1, afterFinish:function(){
		    $(id1).setOpacity(0.1);}
		  
		  });
		  }
		  });
		 dataLayer3.className='visible';
	     }
	    else
	     {
          dataLayer1.className='novisible';
		  $(id1).setOpacity(0); 

		new Effect.Opacity(dataLayer3,{duration:1.2,from:0.1,to:0.95, beforeStart:function()
		  {
		  new Effect.Opacity(dataLayer2,{duration:1.1,from:1,to:0.1, afterFinish:function(){
		     $(id2).setOpacity(0.1); }
		  
		  });
		  }
		  });
		  
		 dataLayer3.className='visible';

	    }
	  
	   $('boton_Ch1').style.display='none';
	   $('boton_Ch2').style.display='block';
	   $('boton_Ch3').style.display='none';
	   $('boton_Ch4').style.display='none';
	 
		   $('boton_Ch2').style.padding='0px 0px 0px 150px';

	return false;
   }
 
 
  function devuelvoImagen(id1, id2, id3)
   {
   
		dataLayer1=document.getElementById(id1);
		dataLayer2=document.getElementById(id2);
		dataLayer3=document.getElementById(id3);
		
//			  $(id2).setOpacity(0); 
        dataLayer2.className='novisible';
	    dataLayer1.className='visible';
		  $(id3).setOpacity(1); 
	    dataLayer3.className='visible';

		new Effect.Opacity(dataLayer1,{duration:1.2,from:0.2,to:1.0, beforeStart:function()
		  {
		  new Effect.Opacity(dataLayer3,{duration:1.5,from:1,to:0, afterFinish:function(){
		    dataLayer3.className='novisible';}
		  
		  });
		  }
		  });
   
   $('boton_Ch2').style.display='none';
   $('boton_Ch1').style.display='block';
	   $('boton_Ch3').style.display='block';
	   $('boton_Ch4').style.display='block';

	
		
   }