//loading...
var myGlobalHandlers = {
  onCreate: function(){
    Element.show('loading');
  },

  onComplete: function() {
    if(Ajax.activeRequestCount == 0){
      Element.hide('loading');
    }
  }
};

Ajax.Responders.register(myGlobalHandlers);

function renderArtist(artist_id) {

  var url = '?action=render_artist_ajax';
  var pars = 'artist_id='+artist_id;

  var myAjax = new Ajax.Request(
    url,
    {
      method: 'post',
      postBody: pars,
      encoding: 'ISO-8859-1',
      onComplete: renderArtistResponse
    });
}

function renderArtistResponse(resp) {
  $('default_01').innerHTML = resp.responseText;
}

function listArtists() {

  var url = '?action=list_artists';
  var pars = '';

  var myAjax = new Ajax.Request(
    url,
    {
      method: 'post',
      postBody: pars,
        encoding: 'ISO-8859-1',
      onComplete: listArtistsResponse
    });
}

function listArtistsResponse(resp) {
  $('default_01').innerHTML = resp.responseText;
}