JS判断checkbox是否选择

  //在没有选中记录时的删除操作
        function ShowConfirm(formID, isDelSelectedRecord, selectedRecordToOpration) {
            var Elements = document.getElementById(formID).elements; //获取目标复选框组所在的Form表单
            if (Elements == null) {
                return false;
            }

            var flag = false;
            for (var i = 0; i < Elements.length; i++) {
                if (Elements[i].type == "checkbox")   //根据对象类型和对象的name属性判断是否为目标复选框
                {
                    if (Elements[i].checked == true)   //根据用于控制的复选框的选中情况判断是否选中目标复选框
                    {
                        flag = true;
                    }
                }
            }

            if (flag) {
                //是否删除所选记录?
                if (window.confirm(isDelSelectedRecord)) {
                    document.getElementById("btn_del").click();
                }
            }
            else {
                //请选择至少一条要删除的记录进行操作!
                alert(selectedRecordToOpration);
                return false;
            }
        }