批量删除文章ID?

(list.php): <form action="del.php" method="post"> <?php $sql="select * from news where leibie='$leibieming'";$r=$mysqli->query($sql); while($rs=$r->fetch_assoc()){ ?> <input type="checkbox" value="<?=$rs[id]?>" /><?=$rs[title]?> <?php } ?> <input type="button" value="删除""></form> 2、处理惩罚页面（del.php）： <?php if($del_id!=""){ $del_num=count($del_id); for($i=0;$i<$del_num;$i++){ $mysqli->query("delete news.......");} echo("<script type='text/javascript'>alert('删除乐成！');history.back();</script>"); }else{ echo("<script type='text/javascript'>alert('请先选择项目！');history.back();</script>"); } ?> 

if(isset($_POST['del_id'])){    $del_id=$_POST['del_id'];    $del_num=count($del_id);    for($i=0;$i<$del_num;$i++){        $mysqli->query("delete news,newscontents from news inner join newscontents on news.Nid=newscontents.nid where news.Nid='$del_id'");        echo $del_id.'删除';    }}else{    echo("<script type='text/javascript'>alert('请先选择项目！');history.back();</script>");}

<form action="delAllZhangJie.php"method="post"><?php    $Name="国际新闻";    $sql="select Nid,Title from news where Class='$Name' order by Nid desc";    $csql=$mysqli->query($sql);    while($rs=$csql->fetch_assoc()){?>        <input type="checkbox" name="del_id[]" value="<?=$rs['Nid']?>" />-<?=$rs['Nid']?>-<?=$rs['Title']?><br><?php    }?>    <input type="submit"  value="删除""></form>