checkbox批量刪除js（全選/全部選）

<script type="text/javascript">
    function seltAll(){
        var chckBoxSign = document.getElementById("ckb");       //ckb 全選/反選的選擇框id
        var chckBox = document.getElementsByName("chckBox");    //所有的選擇框其那麼都是chckBox
        var num = chckBox.length;
        if(chckBoxSign.checked){
            for(var index =0 ; index<num ; index++){
                chckBox[index].checked = true;
                }
        }else{
            for(var index =0 ; index<num ; index++){
                chckBox[index].checked = false;
                }
            }
        }

    function deleSeltedRecords(){
        var chckBox = document.getElementsByName("chckBox");
        var num = chckBox.length;
        var ids = "";
        for(var index =0 ; index<num ; index++){
            if(chckBox[index].checked){
                ids += chckBox[index].value + ",";
            }
        }
        if(ids!=""){
            if(window.confirm("確定刪除所選記錄？")){
                $.ajax( {
                    type : "post",
                    url : '../g3/history-no!batchDelete.action?ids=' + ids, //要自行刪除的action
                    dataType : 'json',
                    success : function(data) {
                        alert("刪除成功");
                        window.location.href = "channel-no.action" ;
                    },
                    error : function(data) {
                        alert("系統錯誤，刪除失敗");
                    }
                });
            }
        }else{
            alert("請選擇要刪除的記錄");
            }
        }
</script>