Loader em iframe com jquery ui

<script>

$(function(){
    $('ul.capitulos li a').on('click', function(e){
        e.preventDefault();
		
        $('<div/>', {'class':'myDlgClass', 'id':'link-'+($(this).index()+1)})
        .html($('<iframe/>', {
            'src' : $(this).attr('href'),
            'style' :'width:100%; height:100%; border:none;'
        })).appendTo('body')
        .dialog({
		
            'title' : $(this).text(),
            'width' : 800,
            'height' :380,
			
            buttons: {
			    "cerrar": function() {
				$(this).dialog("close");
				}
				     },
			modal: true,
			show: {
                effect: "blind",
                duration: 500
                  },
            hide: {
                effect: "blind",
                duration: 500
                  }
        });
    });
});


</script>