text: var autocompleters = new Array();
  
  function additionalFieldForItem(form_id, fs_or_ec_id){
      var elements =  $(form_id).getElements();
      var item;
      var substance_autocomplete;
      for (var i=0;i<elements.length;i++)
      {
        var id = elements[i].id;
        if (id.match('measured_item_id'))
          item = elements[i];
        if (id.match('autocomplete_input'))
          substance_autocomplete = elements[i];
      }
  
      //check if the selected item is concentration
      var selectedIndex = item.selectedIndex;
      var option_select = item.options[selectedIndex];
  
      if (option_select.text == 'concentration'){
          substance_autocomplete.disabled = false;
          fade(fs_or_ec_id + 'growth_medium_or_buffer_description')
          appear(fs_or_ec_id + 'substance_condition_factor')
      }
      else if (option_select.text == 'growth medium' || option_select.text == 'buffer'){
          fade(fs_or_ec_id + 'substance_condition_factor')
          appear(fs_or_ec_id + 'growth_medium_or_buffer_description')
      }
      else{
          fade(fs_or_ec_id + 'substance_condition_factor')
          fade(fs_or_ec_id + 'growth_medium_or_buffer_description')
      }
  }
  
  function appear(element_id){
     Effect.Appear(element_id, { duration: 0.5 });
  }
  
  function fade(element_id){
     Effect.Fade(element_id, { duration: 0.25 });
  }
  