购物车数量变化 价格随之变化 如何存入数据库
我在做一个购物车  
数量可以变化   价格也随着变化
购物车下面是总价格  
本人对js不是很熟悉   所以从网上找了段代码
    <td> <input   size= "3 "   name= "count "     value= " <%=number%> "   id= "count "   type= "text "   onChange= "doSum(); "> </td>
                <input   name= "price "   id= "price "   type= "hidden "   value= " <%=price%> ">  
                  <td> <input     size= "3 "     name= "sum "       id= "sum "     value= " <%=price%> "   type= "text "   readonly> </td>

JS:
    <script       language= "JavaScript ">      
    function       doSum(){      
                document.all[ 'sum '].value       =       document.all[ 'price '].value       *       document.all[ 'count '].value;

    }      
    </script>

可是问题也随之出现   一个物品的时候   还可以实现   要是购物车有都个产品   就不能了,   而且我有一张购物车的表   但是这数量的变化   和总价格的变化   如果存入到数据库中   .
谢谢各位

------解决方案--------------------
不好意思 有些错误

<table> <tr>
<td> <input size= "3 " name= "count " value= " <%=number%> " id= "count " type= "text " onChange= "doSum(); "> </td>
<input name= "count_old " id= "count_old " type= "hidden " value= " <%=number%> ">
<input name= "price " id= "price " type= "hidden " value= " <%=price%> ">
<td> <input size= "3 " name= "sum " id= "sum " value= " <%=price%> " type= "text " readonly> </td>
<input name= "sum_old " id= "sum_old " type= "hidden " value= " <%=price%> ">

</tr> </table>
<script language= "JavaScript ">
function doSum(){
document.all[ 'sum '].value = Number(document.all[ 'price '].value) * Number(document.all[ 'count '].value);

}
</script>