var fb=$('feature_box');
var f_id = 48;
var f_on = 0;
var features;
new Ajax.Request('/json/feature/?search=10', {
  method:'get',
  onSuccess: function(transport){
    var json = transport.responseText.evalJSON();
    features = json.results;
    for (var i=0;i<json.results.length;i++) {
        if (json.results[i].id==f_id) {
           f_on = i;
        }
    }
  }
});

function showNext( pe ) {
    f_on = (f_on + 1) % features.length;
    var chosen = features[f_on];
    fb.update( '<a id="feature_link" href="'+chosen.link+'"><img id="feature_img" src="'+chosen.value+'" border="0" alt="misc" height="243" width="590"/></a></div>' );
}
new PeriodicalExecuter(showNext, 10);