// JavaScript Document
  var m = Math.random();
  var index = Math.floor(m * 13 + 1);
  var ruta = 'http://www.lobo-solitario.com/imagenes/fondos/' + elec + '_' + index + '.gif';
if (document.all)
document.body.style.cssText='background:black url("' + ruta + '") no-repeat fixed right top';