var form = document.getElementById("form2");

var field = form.elements["test2"];
var option = Dining.getSelectedOption(form, field);
var message = "";
for (var i = 0, len = option.length; i < len; i++) {
message += "Select id:" + option[i].id + "\nSelected name:" + option[i].name + "\nSelected value:" + option[i].value + "\n\n";
}
alert(message);
/*获取选中的选项*/
getSelectedOption: function (selectform, selectionfield) {
var result = [];
var option = null;
for (var i = 0; i < selectionfield.length; i++) {
option = selectionfield[i];
if (option.checked) {
result.push(option);
}

}
return result;

}
<form id='form2'>

<label>排序：</label><input id='aaaaa' type='checkbox' name='test2' value='1'>

<label for='aaaaa'>月销量</label><input id='bbbbb' type='checkbox' name='test2' value='2'>

<label for='bbbbb'>评分</label><input id='ccccc' type='checkbox' name='test2' value='3'>

<label for='ccccc'>优惠</label> <br style='clear:both'><label>分类：</label><input id='ddddd' type='checkbox' name='test2' value='4'>

<label for='ddddd'>商务套餐</label><input id='eeeee' type='checkbox' name='test2' value='5'>

<label for='eeeee'>凉菜</label><input id='fffff' type='checkbox' name='test2' value='6'>

</form>",