ecshop 多选 购物车 大家看看还少什么

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<!-- {if $related_goods} -->
<!--{foreach from=$related_goods item=releated_goods_data}-->
 <div class="goodsMod" style="width:105px;">
 <a href="{$releated_goods_data.url}"><img src="{$releated_goods_data.goods_thumb}" alt="{$releated_goods_data.goods_name}" style="width:45px;height:45px;" /></a><br />
 <p><a href="{$releated_goods_data.url}" title="{$releated_goods_data.goods_name}">{$releated_goods_data.short_name|truncate:"35"}</a></p>
 <font class="f1">
 
<strong><font color="#c53c19" font-weight:"bold"><b>{$releated_goods_data.shop_price}</b><br /></font>

</font>
  <br>
<input name="mul_add_good_id[]" type="checkbox" value="{$releated_goods_data.goods_id}" class="mul_add_good_id">加入购物车  
 </div><!--{/foreach}-->
<br><br />
<center><img src="images/mul_addcart.jpg" onClick="mul_add_to_cart();" /></center>
<script type="text/javascript" language="javascript">
var getElementsByClassName = function (searchClass, node,tag) {  
    if(document.getElementsByClassName){          return  document.getElementsByClassName(searchClass)      }else{          node = node || document;          tag = tag || "*";          var classes = searchClass.split(" "),          elements = (tag === "*" && node.all)? node.all : node.getElementsByTagName(tag),          patterns = [],          returnElements = [],          current,          match;          var i = classes.length;          while(--i >= 0){              patterns.push(new RegExp("(^|\\s)" + classes[i] + "(\\s|$)"));          }          var j = elements.length;          while(--j >= 0){              current = elements[j];              match = false;              for(var k=0, kl=patterns.length; k<kl; k++){                  match = patterns[k].test(current.className);                  if (!match)  break;              }              if (match)  returnElements.push(current);           }          return returnElements;      }  }
function mul_add_to_cart()
{
   var my_elems =  getElementsByClassName("mul_add_good_id");
   var sel_num =0;
   var sel_id ="";
for (var i=0; i < my_elems.length; i++)
  {
if (my_elems[i].checked)
{
  sel_num +=1;
  sel_id  += i==0 ? my_elems[i].value:"," + my_elems[i].value;
     }
  }
  if(sel_num==0)
  {
alert("请至少选择一项需要加入的附件"); 

  }
  else
  {
  Ajax.call('flow.php?step=mul_add_to_cart', 'goods_ids=' + sel_id, mul_add_to_cart_response, 'POST', 'JSON');  
  }
}

function mul_add_to_cart_response(result)
{
  if (result.error > 0)
  {
alert("加入沟物车失败");
  }
  else
  {
 location.href = "flow.php?step=cart";  
  }
}
</script>
<!--{else}-->
<img src="../images/nopic.gif">
<!-- {/if} -->
网站在http://dxpwswws1.h107.sxcenter.cn/ecshop/goods.php?id=13