options的回掉函数参数怎么传递？

有点不太明白beforeSubmit跟success的回掉函数是如何获取参数信息的，有人能跟我说下这个过程么
function singleDel(itemId) {
        var delChkUrl = $("#delCheckAction").val();
        
        var options = {
                beforeSubmit: showDeleteCheckRequest,
                success:      showDeleteCheckResponse,
                type:         'post',
                dataType:     "script",
                data:{
                    'itemId':itemId
                },
                url:          delChkUrl
        };
        $('#form1').ajaxSubmit(options);
    }

    function showDeleteCheckRequest(formData, jqForm, options) {
        return true;
    }

    function showDeleteCheckResponse(responseText, statusText, xhr, $form) {
        responseText = $.parseJSON(responseText);
        var status = responseText[0].deleteAble;
        if (status == "true") {
            var itemId = responseText[0].itemId;
            var delUrl = $("#delAction").val();
tipShow('#confirmDiv');
objDelUrl = delUrl;
            objItemId = itemId;
        } else if (status == "false") {
            alert(responseText[0]._mes);
        } else {
            alert("删除失败！");
        }