how do I get the checked event to fire with a radio button?

[Eskimo]

<asp:repeater id="Repeater1" runat="server">
<HeaderTemplate>
<table class="" cellspacing="4" cellpadding="4" width="100%">
<tr style="background-color:#E0E0E0">
<td></td>
<td>Path</td>
<td>File</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr style="background-color:#F0F0F0">
<td>
<asp:RadioButton id="RadioButton1" GroupName="Files"
OnCheckedChanged=RadioButton1_CheckedChanged AutoPostBack=True Text='<%#
DataBinder.Eval(Container.DataItem,"Path") %>' runat="server">
</asp:RadioButton>
</td>
<td align="left"><%# DataBinder.Eval(Container.DataItem,"Path")
%></td>
<td align="left"><%# DataBinder.Eval(Container.DataItem,"File")
%></td>
</tr>
</ItemTemplate>
<AlternatingItemTemplate>
<tr style="background-color:#E0E0E0">
<td>
<asp:RadioButton id="Radiobutton2" GroupName="Files"
OnCheckedChanged=RadioButton2_CheckedChanged AutoPostBack=True Text='<%#
DataBinder.Eval(Container.DataItem,"Path") %>' runat="server">
</asp:RadioButton>
</td>
<td align="left"><%# DataBinder.Eval(Container.DataItem,"Path")
%></td>
<td align="left"><%# DataBinder.Eval(Container.DataItem,"File")
%></td>
</tr>
</AlternatingItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:repeater>