<script type="text/javascript">
            $(function(){
                $.ajax({
                    type:'post',
                    url:'selectsql.php',
                    dataType:'json',
                    success:function(data){
                        var str='';
                        for(var i in data){
                            alert (data[i]['wid']);
                            str+="<div>这是第"+data[i]['wid']+"条留言\
                            "+data[i]['con']+"\
                            留言时间"+data[i]['addtime']+"署名\
                            "+data[i]['wname']+"</div>";
                        }
                        $('body').append(str);
                    }
                })
            })
        </script>