问追加功能不会将关闭菜单添加到先前创建的关闭菜单或上一行

EN

$(document).ready(function(){
    $('.textfield').keyup(function(e){  
                    var query_string = $.trim($(this).val());
        //alert(query_string.length);
                var count=query_string.length;
        if(count!==0)
                {                           
         setTimeout(function(){

                     $.ajax({              
            type: "post",
            url: "autosuggestion.php",
            data: { name:query_string},
                                                cache:false,
            success: function(data)

            { 

                                                    $('#dropdownlist').html(data);

                                                    $('#dropdown  li').one('click',function(e)
                                                {                          


                                                                             var return_value = $(this).text();
                                                                             var value= $('<li></li>').text(return_value).addClass('appenddata');
                                                                             $('#skill').append(value);
                                                                             var code='&#10006';
                                                                             var a=$('<span></span>').html(code);
                                                                             $('.appenddata').append(a);     


                                                });

            }
        });
                 },1500);    

        }  
        });
});

<?php
mysql_connect('localhost','root','');
mysql_select_db('questions');
if(isset($_POST['name']))
{            
    $username = mysql_real_escape_string(trim($_POST['name']));
    $sql = "SELECT `subject` FROM `suggestion` WHERE `subject` LIKE '$username%'";
    $myquery = mysql_query($sql) or die(mysql_error());

    if(mysql_num_rows($myquery) !=0)
    {               echo '<div id="dropdown">';
        while(($row = mysql_fetch_array($myquery ))!==false)
        {          
            echo '<li>'.$row['subject'];
        }
                            echo '</li></div>';

    }
    else
    {   
                            echo '<div id="innerinput12"> Kindly select from Drop-down list</div>';
                            echo "<script type='text/javascript'>var id = document.getElementById('innerinput12');
                                 setTimeout(function(){id.style.display = 'none';},2500); </script>";
    }



}



?>