dedecms购物车优化提交数量和自定义字段到购物车的方法

<form id="formcar" name="formcar" method="post" action="{dede:field name='phpurl'/}/posttocar.php">

<form id="formcar" name="formcar method="post" action="{dede:field name='phpurl'/}/posttocar.php">
....
<p>尺码：
 <select name="guige" >
  <option value="155/76">155/76</option>
  <option value="155/78">155/78</option>
  <option value="155/80">155/80</option>
  <option value="155/82">155/82</option>
</select>
</p>
<p>
<input name="buynum" type="text" id="buynum" value="1"/>
</p>
.....
</form>

$rows['title']     = $rs['title'];

$rows['guige'] = $_POST['guige'];
$rows['buynum'] = $_POST['buynum'];

{dede:array.Items}

<td height="23"><span class="price">{dede:value.price/}</span ></td>
<!--后面增加-->
<td height="23">{dede:value.guige/}</td>

$cart->addItem($id, $rows);
ShowMsg("已添加加到购物车！", "javascript:history.go(-1);", false, 500);
//修改提示字段,跳转时间为500毫秒,,返回上一页