<form name="del_form" action="del.php" method="post">
  <?php
        $result=mysql_query("select * from news");
        while($rs=mysql_fetch_array($result)){
     ?>
        <input name="del_id[]" type="checkbox" id="del_id[]" value="<?=$rs[id]?>" /><?=$rs[title]?>
     <?php
        }
     ?>
   </form>

  <?php [separator]
     if($del_id!=""){
             $del_num=count($del_id);
             for($i=0;$i<$del_num;$i++){
                 mysql_query("Delete from news where id='$del_id[$i]'");
             }  
             echo("<script type='text/javascript'>alert('删除成功！');history.back();</script>");
      }else{
             echo("<script type='text/javascript'>alert('请先选择项目！');history.back();</script>");
      }
    ?>  

<script>function checkall(form, prefix, checkall) {
for(var i = 0; i < form.elements.length; i++) {
var e = form.elements[i];
if(e.name != checkall && (!prefix || (prefix && e.name.match(prefix)))) {
e.checked = form.elements[checkall].checked;
}
}
}</script>
<form>
<input type="checkbox" name="chkall" onclick="checkall(this.form, 'del', 'chkall')">全选
<input type="checkbox" name="del[]" value=1>删除1
<input type="checkbox" name="del[]" value=2>删除2
<input type="checkbox" name="del[]" value=3>删除3
<input type="checkbox" name="del[]" value=4>删除4
<input type="submit" name="modsubmit" value="提交">
</form>