当easyui datagrid无数据时,显示特定值。如:没有数据

<!DOCTYPE html>
< html >
< head >
     < meta  charset = "UTF-8" >
     < title >Basic DataGrid - jQuery EasyUI Demo</ title >
     < link  rel = "stylesheet"  type = "text/css"  href = "../../themes/default/easyui.css" >
     < link  rel = "stylesheet"  type = "text/css"  href = "../../themes/icon.css" >
     < link  rel = "stylesheet"  type = "text/css"  href = "../demo.css" >
     < script  type = "text/javascript"  src = "../../jquery-1.8.0.min.js" ></ script >
     < script  type = "text/javascript"  src = "../../jquery.easyui.min.js" ></ script >
     < script >
     var myview = $.extend({},$.fn.datagrid.defaults.view,{
     onAfterRender:function(target){
         $.fn.datagrid.defaults.view.onAfterRender.call(this,target);
         var opts = $(target).datagrid('options');
         var vc = $(target).datagrid('getPanel').children('div.datagrid-view');
         vc.children('div.datagrid-empty').remove();
         if (!$(target).datagrid('getRows').length){
             var d = $('< div  class = "datagrid-empty" ></ div >').html(opts.emptyMsg || 'no records').appendTo(vc);
             d.css({
                 position:'absolute',
                 left:0,
                 top:50,
                 width:'100%',
                 textAlign:'center'
             });
         }
     }
     });
     $(function(){
         var list=[];//数据列表为空
     
         $('#dg').datagrid({
               data: list,
             view: myview,
               emptyMsg: 'no records found'
   
         });
     })
     </ script >
</ head >
< body >
     < h2 >Basic DataGrid</ h2 >
     < div  class = "demo-info" >
         < div  class = "demo-tip icon-tip" ></ div >
         < div >The DataGrid is created from markup, no JavaScript code needed.</ div >
     </ div >
     < div  style = "margin:10px 0;" ></ div >
     
      < table  id = "dg"  title = "Surveys"  class = "easyui-datagrid"  style = "width:550px;height:250px"   toolbar = "#toolbar"   rownumbers = "true"  fitColumns = "true"  singleSelect = "true" >  
   < thead >  
     < tr >  
         < th  field = "id"  width = "20" >Id</ th >  
         < th  field = "name"  width = "50" >Name</ th >  
         < th  field = "number"  width = "50" >Number</ th >  
         < th  field = "description"  width = "50" >Description</ th >  
     </ tr >  
   </ thead >  
  </ table >
 
</ body >
</ html >