$(document).ready(function(){
     $('a.ativa_lightbox').lightBox({
        fixedNavigation:false,
        txtImage: 'Imagem',
        txtOf: 'de',
        imageLoading: media_url()+'img/icons/lightbox-ico-loading.gif',
        imageBtnPrev: media_url()+'img/icons/anterior.gif',
        imageBtnNext: media_url()+'img/icons/proxima.gif',
        imageBtnClose: media_url()+'img/icons/lightbox-btn-close.gif'
    });
});