function ref_art() {
  new Ajax.Updater('replaced', 'ref_art.html', {
      method : 'get',
     onCreate:  function() {
        $('indicator').show();
      },
      onComplete: function(){
        $('indicator').hide();
        new Effect.SlideDown('replaced');
        }
      }); 
    
    return false;
};

function ref_cot() {
   new Ajax.Updater('replaced', 'ref_cot.html', {
       method : 'get',
      onCreate:  function() {
        $('indicator').show();
        },
      onComplete: function() {
        $('indicator').hide();
        new Effect.SlideDown('replaced');
        }
  
      }); 
    return false;
}