function volver(){
	history.go(-1);
}

function MM_swapImgRestore() 
{  var i,x,a=document.MM_sr; 
   for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) 
     x.src=x.oSrc;
} 
function MM_preloadImages()
{   var d=document; 
 if(d.images)	 
  { 
  if(!d.MM_p) d.MM_p=new Array();    
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; 
    for(i=0; i<a.length; i++)    
      if (a[i].indexOf("#")!=0)
      { d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}	
  }
} 
function MM_findObj(n, d) 
{    var p,i,x;  if(!d) d=document; 
    if((p=n.indexOf("?"))>0&&parent.frames.length) 
    {    d=parent.frames[n.substring(p+1)].document; 
         n=n.substring(0,p);
    }  
    if (!(x=d[n])&&d.all) 
      x=d.all[n]; 
    for (i=0;!x&&i<d.forms.length;i++) 
       x=d.forms[i][n];   
    for(i=0;!x&&d.layers&&i<d.layers.length;i++) 
       x=MM_findObj(n,d.layers[i].document); 
    return x;
    } 
function MM_swapImage()  
{  var i,j=0,x,a=MM_swapImage.arguments;  
   document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)    
   if ((x=MM_findObj(a[i]))!=null)
       {document.MM_sr[j++]=x; 
        if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2]; 
	}
}