function haha() {  
    jQuery.post("addComment!comment.action",  
     function aa(data) {  
          data = eval(data);//POST方法必加，ajax方法自动处理了  
          alert(data[0].userId);  
          alert(data[0].userName);  
    },  
    "json"  
    );  
      
    jQuery.ajax({  
        type:"post",  
        url:"addComment!comment.action",  
        dataType:"json",  
        success: function aa(data) {  
              alert(data[0].userId);  
              alert(data[0].userName);  
        }  
    });  
}  
 
 

//javascript/7012