get Radiobutton value in C# code behind

Hi,


I am working on web application using C#, and ASP.net 2.0

I have created 3 radio buttons code is below

I am not able to get the values, that what user has clicked

<asp:RadioButton ID="RadioButton1" runat="server" Checked="True" Text="Both" GroupName="mode" />&nbsp;<asp:RadioButton
        ID="RadioButton2" runat="server" Text="Shortfall" GroupName="mode" />
    <asp:RadioButton ID="RadioButton3" runat="server" Text="Overages" GroupName="mode" />
   
I mean if user has selected Both or Shortfall or Overages from the radiobutton

Please help

Thanks