function showImage(img,alt){
  function whenLoading(){
    document.getElementById('preview').innerHTML = '<div class="cargando">Cargando...</div>';
  }
  var results_div = 'preview';
  var mysack = new sack("image.php");
  mysack.method = 'POST';
  mysack.setVar( "img", img );
  mysack.setVar( "alt", alt );
  mysack.setVar( "from", 'showImage' );
  mysack.element = results_div;
  mysack.onLoading = whenLoading;
  mysack.runAJAX();
  return false;
}

function showProject(projectId){
  function whenLoading(){
    document.getElementById('content').innerHTML = '<div class="cargando">Cargando...</div>';
  }
  var results_div = 'content';
  var mysack = new sack("projects-es.php");
  mysack.method = 'POST';
  mysack.setVar( "pj_id", projectId );
  mysack.setVar( "from", 'showProject' );
  mysack.element = results_div;
  mysack.onLoading = whenLoading;
  mysack.runAJAX();
  return false;
}