var a_ = fromHTML(a.getData(field));

    var b_ = fromHTML(b.getData(field));

    // extract name from table

    a_ = get_group_name(a_)

    b_ = get_group_name(b_)          

    var comp = YAHOO.util.Sort.compare;

    var compState = comp(a_, b_, desc);

    return compState;

};

var dateSort = function(a, b, desc, field) {

    var a_ = fromHTML(a.getData(field));

    var b_ = fromHTML(b.getData(field));

    // extract name from table

    a_ = get_date(a_)

    b_ = get_date(b_)          

    var comp = YAHOO.util.Sort.compare;

    var compState = comp(a_, b_, desc);

    return compState;

};

	  var a_ = fromHTML(a.getData(field));

	  // extract url text from string nodes 

	  a_ = get_link(a_)

	  b_ = get_link(b_)

	  var comp = YAHOO.util.Sort.compare;

	  var compState = comp(a_, b_, desc);

	  return compState;

}

var addPermAction = function(_html, users_list, groups_list){

    var elmts = YUD.getElementsByClassName('last_new_member');

    var last_node = elmts[elmts.length-1];

    if (last_node){

       var next_id = (YUD.getElementsByClassName('new_members')).length;

       _html = _html.format(next_id);

       last_node.innerHTML = _html;

       YUD.setStyle(last_node, 'display', '');

       YUD.removeClass(last_node, 'last_new_member');

       MembersAutoComplete("perm_new_member_name_"+next_id, 

               "perm_container_"+next_id, users_list, groups_list);          

       //create new last NODE

       var el = document.createElement('tr');

       el.id = 'add_perm_input';

       YUD.addClass(el,'last_new_member');

       YUD.addClass(el,'new_members');

       YUD.insertAfter(el, last_node);

    }	

}

  myDataSource.doBeforeCallback = function(req,raw,res,cb) {

      // This is the filter function

      var data     = res.results || [],

          filtered = [],

          i,l;

      if (req) {

          req = req.toLowerCase();

          for (i = 0; i<data.length; i++) {

              var pos = data[i].raw_username.toLowerCase().indexOf(req)

              if (pos != -1) {

                  filtered.push(data[i]);

              }

          }

          res.results = filtered;

      }

      YUD.get('user_count').innerHTML = res.results.length;

      return res;

  }

  // main table sorting

  var myColumnDefs = [

      {key:"gravatar",label:"",sortable:false,},

      {key:"username",label:"${_('username')}",sortable:true,

      },

      {key:"firstname",label:"${_('firstname')}",sortable:true,},

      {key:"lastname",label:"${_('lastname')}",sortable:true,},

      {key:"last_login",label:"${_('last login')}",sortable:true,

          sortOptions: { sortFunction: lastLoginSort }},

      {key:"active",label:"${_('active')}",sortable:true,},

      {key:"admin",label:"${_('admin')}",sortable:true,},

      {key:"ldap",label:"${_('ldap')}",sortable:true,},

      {key:"action",label:"${_('action')}",sortable:false},

  ];

  var myDataTable = new YAHOO.widget.DataTable("users_list_wrap", myColumnDefs, myDataSource,{

    sortedBy:{key:"username",dir:"asc"},

    paginator: new YAHOO.widget.Paginator({

        rowsPerPage: 15,

        alwaysVisible: false,

        template : "{PreviousPageLink} {FirstPageLink} {PageLinks} {LastPageLink} {NextPageLink}",

        pageLinks: 5,

        containerClass: 'pagination-wh',

        currentPageClass: 'pager_curpage',

        pageLinkClass: 'pager_link',

        nextPageLinkLabel: '>',

        previousPageLinkLabel: '<',

        firstPageLinkLabel: '<<',