请问这个js验证错在哪？

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="DiaoChaInfo.aspx.cs" Inherits="DiaoChaInfo" %><!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 runat="server">
    <title></title>
    <script type="text/javascript" language="javascript">
        function checkreg() {
            j = 0;
            for (i = 0; i < document.form1.Repeater1.RadioButtonList1.length; i++) {
                if (document.form1.Repeater1.RadioButtonList1.checked == true) {
                    j++;
                }
            }
            if (j == 0) {
                alert('请选择');
                return false;
            }
            return true
        } 
    </script>
</head>
<body>
    <form id="form1" runat="server" onsubmit="return checkreg()">
    <div>
        <div>
            <asp:Label ID="DiaoChaTitle" runat="server" Text=""></asp:Label></div>
        <div>
            <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">
                <ItemTemplate>
                    <asp:HiddenField ID="HiddenField1" runat="server" Value='<%#Eval("timuID")%>' />
                    <%#Eval("timuName")%>
                    <asp:RadioButtonList ID="RadioButtonList1" runat="server" DataTextField="answerName"
                        DataValueField="answerID">
                    </asp:RadioButtonList>
                </ItemTemplate>
            </asp:Repeater>
        </div>
        <asp:Button ID="submit" runat="server" Text="提交答卷" />
    </div>
    </form>
</body>
</html>
请问这个js验证错在哪？

解决方案 »

  1.   

    document.form1.Repeater1.RadioButtonList1.length你这样是找不到对象的。服务端的ID跟客户端的ID是没法共用的。
      

  2.   

    <%=RadioButtonList1.ClientID %>
      

  3.   

    document.form1.Repeater1.RadioButtonList1.length取不到的 我建议lz运行程序后 按F12好好看看源码里是什么样子的
      

  4.   

    document.form1.Repeater1.RadioButtonList1.length
    在客户端是不能直接 不能访问的
    查看源码 用生成的html代码中id
      

  5.   

    <div>
      <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">
    改成 <div id="chk_all"> 
      <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">js如下修改
    j = 0;
    var chk_all = document.getElementById("chk_all");
    var check = chk_all.getElementsByTagName("radio");
      for (i = 0; i < check.length; i++) {
      if (check[i].checked == true) {
      j++;
      }
      }