Hello,
first do this ,take radiobutton list instead of radio buttons for gender because user could select either MALE or FEMALE , can't be select BOTH :)
so take radiobutton list and try with this ,
<asp:RadioButtonList ID="radGender" runat="server" RepeatDirection="Horizontal" Width="75%">
<asp:ListItem Value="M">Male</asp:ListItem>
<asp:ListItem Value="F">Female</asp:ListItem><br />
</asp:RadioButtonList>
if (ds.Tables[0].Rows[i]["Gender"].ToString() == "M")
{
radGender.SelectedValue = "M";
}
else
{
radGender.SelectedValue = "F";
}
If its work for you , acknowledge here.
Thank you.