获取隐藏字段的值

我的前台代码是

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="comment.aspx.cs" Inherits="comment" %>



<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">



<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head1" runat="server">

    <title>无标题页</title>

    <script  type="text/javascript"  language="javascript">

    //全部评论

function btnall()

{

            document.getElementById("hidall").value="2";

    }

    

//好评





    function btnbest()

   {

       

            document.getElementById("hidbest").value="5"; 

    }

    

    //中评

    function btngood()

    {

    

            document.getElementById("hidgood").value="3";

     }

    

//差评

function btnbad()

{

  document.getElementById("hidbad").value="1";

 }

    

    

    </script>

    <style type="text/css">

        .style1 {

            width: 161px;

        }

    </style>

</head>

<body>

    <form id="form1" runat="server">

    <div>

    

      <table width="100%" border="0">

        <tr>

          <td height="35" align="left"  onclick="btnall()" class="style1"><div id="h_help1">全部评论</div></td>

          <td width="65"  onclick ="btnbest()"><div id="h-help2">好评</div></td>

          <td width="67" onclick="btngood()"><div id="h_help3">中评 </div> </td>

          <td width="67" onclick="btnbad()"><div id="h_bad">差评 </div> </td>

</tr> 

          </table> 

<%--    全部评论--%>

   <input id="hidall" type="hidden" />

   <%-- 好评--%>

    <input id="hidbest" type="hidden" />

   <%-- 中评--%>

   <input id="hidgood" type="hidden" />

  <%-- 差评--%>

  <input id="hidbad" type="hidden" />

    </div>

    </form>

</body>





</html>

怎么当点击差评或好评之后，怎么在后台获取那四个隐藏字段的值呀？