YUD.get(container).innerHTML='ERROR';

};

YAHOO.util.Event.onDOMReady(function(){

  var D = YAHOO.util.Dom;

  var E = YAHOO.util.Event;

  //definition of containers ID's

  var available_container = 'available_members';

  var selected_container = 'users_group_members';

  //form containing containers id

  var form_id = 'edit_users_group';

  //temp container for selected storage.

  var cache = new Array();

  var av_cache = new Array();

  var c =  D.get(selected_container);

  var ac = D.get(available_container);

  //get only selected options for further fullfilment

  for(var i = 0;node =c.options[i];i++){

      if(node.selected){

          //push selected to my temp storage left overs :)

          cache.push(node);

      }

  }

  //get all available options to cache

  for(var i = 0;node =ac.options[i];i++){

          //push selected to my temp storage left overs :)

          av_cache.push(node);

  }

  //fill available only with those not in choosen

  ac.options.length=0;

  tmp_cache = new Array();

  for(var i = 0;node = av_cache[i];i++){

      var add = true;

      for(var i2 = 0;node_2 = cache[i2];i2++){

          if(node.value == node_2.value){

              add=false;

              break;

          }

      }

      if(add){

          tmp_cache.push(new Option(node.text, node.value, false, false));

      }

  }

  for(var i = 0;node = tmp_cache[i];i++){

      ac.options[i] = node;

  }

  function prompts_action_callback(e){

      var choosen = D.get(selected_container);

      var available = D.get(available_container);

      //get checked and unchecked options from field

      function get_checked(from_field){

          //temp container for storage.

          var sel_cache = new Array();

          var oth_cache = new Array();

          for(var i = 0;node = from_field.options[i];i++){

              if(node.selected){

                  //push selected fields :)

                  sel_cache.push(node);

              }

              else{

                  oth_cache.push(node)

              }

          }

          return [sel_cache,oth_cache]

      }

      //fill the field with given options

      function fill_with(field,options){

          //clear firtst

          field.options.length=0;

          for(var i = 0;node = options[i];i++){

                  field.options[i]=new Option(node.text, node.value,

                          false, false);

          }

      }

      //adds to current field

      function add_to(field,options){

          for(var i = 0;node = options[i];i++){

                  field.appendChild(new Option(node.text, node.value,

                          false, false));

          }

      }

      // add action

      if (this.id=='add_element'){

          var c = get_checked(available);

          add_to(choosen,c[0]);

          fill_with(available,c[1]);

      }

      // remove action

      if (this.id=='remove_element'){

          var c = get_checked(choosen);

          add_to(available,c[0]);

          fill_with(choosen,c[1]);

      }

      // add all elements

      if(this.id=='add_all_elements'){

          for(var i=0; node = available.options[i];i++){

                  choosen.appendChild(new Option(node.text,

                          node.value, false, false));

          }

          available.options.length = 0;

      }

      //remove all elements

      if(this.id=='remove_all_elements'){

          for(var i=0; node = choosen.options[i];i++){

              available.appendChild(new Option(node.text,

                      node.value, false, false));

          }

          choosen.options.length = 0;

      }

  }

  E.addListener(['add_element','remove_element',

                 'add_all_elements','remove_all_elements'],'click',

                 prompts_action_callback)

  E.addListener(form_id,'submit',function(){

      var choosen = D.get(selected_container);

      for (var i = 0; i < choosen.options.length; i++) {

          choosen.options[i].selected = 'selected';

      }

  });

});