layui 获取radio单选框选中的值

<div class="layui-form-item">
     <label class="layui-form-label" style="width:100px">是否已购买：</label>
     <div class="layui-input-block" id="IsPurchased">
           <input type="radio"  name="t" value="是" title="是" />
           <input type="radio"  name="t" value="否" title="否" />
     </div>
</div>


//IsPurchased: $('#IsPurchased input[name="t"]:checked ').val()//获取选中的值