gridview中radiobutton只能单选

<script type="text/javascript">
    function demo2(sss)
    {
  
    var es=document.getElementsByTagName("input");
      for(var i=0;i <es.length;i++)
　    {
　　    if (es[i].type=="radio")
　　    {
　　      if(sss.id!=es[i].id)
　　      {
　　         es[i].checked=false;
　　      }
　　     
　　    }
　    }
    }
    </script>

 

 <asp:GridView ID="GridView1" runat="server"
            onrowdatabound="GridView1_RowDataBound">
            <Columns>
                <asp:TemplateField>
                <ItemTemplate>
                   
                    <asp:RadioButton ID="RadioButton1" runat="server"  onclick="demo2(this)" />
                </ItemTemplate>
                </asp:TemplateField>
                <asp:BoundField DataField="UserName" HeaderText="名字" />
                <asp:BoundField DataField="UserCode" HeaderText="aaa" />
                <asp:TemplateField>
                <ItemTemplate>
                <asp:HyperLink ID="HyperLink1" runat="server">HyperLink</asp:HyperLink>
                </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>