선택삭제 도움좀 부탁드립니다

<form method="post" onsubmit="return fnew_submit(this);"><input type="hidden" name="pressed" value=""><table> <tr>     <th scope="col">        <label for="all_chk" class="sound_only">목록 전체</label>        <input type="checkbox" id="all_chk">    </th></tr><tr>    <td class="td_chk">        <label for="chk_bn_id_<?php echo $i; ?>" class="sound_only"><?php echo $num?>번</label>        <input type="checkbox" name="chk_bn_id[]" value="<?php echo $i; ?>" id="chk_bn_id_<?php echo $i; ?>">        <input type="hidden" name="bo_table[<?php echo $i; ?>]" value="<?php echo $list[$i]['bo_table']; ?>">        <input type="hidden" name="wr_id[<?php echo $i; ?>]" value="<?php echo $list[$i]['wr_id']; ?>">    </td></tr></table> <div class="sir_bw02 sir_bw">    <input type="submit" name="submit_button" value="선택삭제" class="btn_submit"> </div></form> <script>$(function(){    $('#all_chk').click(function(){        $('[name="chk_bn_id[]"]').attr('checked', this.checked);    });}); function fnew_submit(f){    document.pressed = f.submit_button.value;     f.pressed.value = document.pressed;     var cnt = 0;    for (var i=0; i<f.length; i++) {        if (f.elements[i].name == "chk_bn_id[]" && f.elements[i].checked)            cnt++;    }     if (!cnt) {        alert(document.pressed+"할 게시물을 하나 이상 선택하세요.");        return false;    }     if (!confirm("선택한 게시물을 정말 "+document.pressed+" 하시겠습니까?\n\n한번 삭제한 자료는 복구할 수 없습니다")) {        return false;    } 	f.action = "./scrap_delete.php";	return true;}</script>