easyui combobox下拉列表的多选值

 1  <input id="cc" class="easyui-combobox" value=""  data-options="
 2                   url:'xxxxxx',
 3                     method:'get',
 4                     valueField:'id',
 5                     textField:'groupName',
 6                      multiple:true,
 7                      panelHeight:'auto',
 8                      loadFilter:function(data){
 9                      return data.data.rows;
10                     }"
11                 /> 
12         <a id="btnGet" class="easyui-linkbutton" data-options="iconCls:'icon-add'">获取已选项集合值</a>

1  $("#btnGet").click(function () {
2                  alert( $('#cc').combobox('getValues'));
3               });