Js php多项选择删除

if("确认删除"){

$num=$_POST['checkbox'];

foreach($num as $v){

        $sql="delete from aa where id =".$v;
        $aa=mysql_query($sql);
        echo "";
    }
}
?>


<script><li>var checkflag = "false";<li>function check(fieldName) {<li>    var field=document.getElementsByName(fieldName);<li>    if (checkflag == "false") {<li>        for (i = 0; i < field.length; i++) {<li>        field[i].checked = true;<li>    }<li>    checkflag = "true";<li>    return "全选";<li> <li>}else {<li>    for (i = 0; i < field.length; i++) {<li>        field[i].checked = false; }<li>        checkflag = "false";<li>        return "全选"; <li>    }<li>}<li></script>