DataGrid中如何绑定RadioButtonList

[miaohuayinggxlx]

这是我的DataGrid的绑定代码：我程序运行的时候，点一个RadioButtonList，再点另外一个RadioButtonList的时候，原来的那个也是选中的。不知道为什么？
<asp:datagrid id="dgDept" runat="server" Width="100%" CellPadding="3" BackColor="White" BorderWidth="1px"
BorderStyle="None" BorderColor="#CCCCCC" AutoGenerateColumns="False" PageSize="15" AllowPaging="True">
<SelectedItemStyle Font-Bold="True" ForeColor="White" BackColor="#669999"></SelectedItemStyle>
<ItemStyle ForeColor="#000066"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="White" BackColor="#006699"></HeaderStyle>
<FooterStyle ForeColor="#000066" BackColor="White"></FooterStyle>
<Columns>
<asp:TemplateColumn HeaderText="选择">
<ItemTemplate>
<asp:CheckBox Runat="server" ID="ChkDeptID" CssClass="Inputedit" BorderStyle="None"></asp:CheckBox>
<asp:Label Runat="server" Visible="False" ID="lblDeptID" Text='<%# DataBinder.Eval(Container.DataItem,"DeptID")%>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn>
<ItemTemplate>
<asp:RadioButtonList ID="listDeptID" Runat="server" AutoPostBack="True">
<asp:ListItem Value="0">选择院系</asp:ListItem>
</asp:RadioButtonList>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="所在院系">
<ItemTemplate>
<asp:Label Runat="server" ID="LblQuesContent" Text='<%# DataBinder.Eval(Container.DataItem,"DeptName")%>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="班级数">
<ItemTemplate>
<asp:Label Runat="server" ID="LblQuesStyle" Text='<%# DataBinder.Eval(Container.DataItem,"ClassNum")%>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
<PagerStyle HorizontalAlign="Right" ForeColor="#000066" BackColor="White" Mode="NumericPages"></PagerStyle>
</asp:datagrid>
<asp:button id="btnNext" Runat="server" CssClass="button" Text="下一步"></asp:button>
</asp:panel>

[miaohuayinggxlx]

怎么没有人回答呀.