var popUpWin=0;
function popUpWindow(URLStr, left, top, width, height)
{
  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }
  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menub ar=no,scrollbars=yes,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}
// JavaScript Document

function alerta(msg)
{
alert(msg);
}
function cambia_imagen(img)
							{
							
							document.getElementById('imagen_galeria').innerHTML='<img src="'+img+'" alt="">';
							}