How do I get the ComboBox to show always as 1 element the element with the same name as the user

Question

This is the code:

 string strConn = (@"Data Source=MY-PC;Initial Catalog=RgpNews;Integrated Security=True;Trusted_Connection=True;connection timeout=30;");

SqlConnection conn = new SqlConnection(strConn);

             try

             {

                conn.Open();

                string selecttable = String.Format(@"SELECT [IdName], [Name] FROM [RgpNews].[dbo].[Users]");

                SqlDataAdapter da = new SqlDataAdapter(selecttable, conn);

                SqlCommandBuilder cmdBldr = new SqlCommandBuilder(da);

                //da.Fill(dt);

                DataTable datat = new DataTable();

                da.Fill(datat);

                comboPaisesbox.DisplayMemberPath = "Name";

                comboPaisesbox.SelectedValuePath = "IdName";

                comboPaisesbox.DataContext = datat;

XMAL Code is;

 <ComboBox Text="Users" x:Name="comboUserbox" Grid.Column="1" HorizontalAlignment="Left" Margin="7,5,0,5" Grid.Row="4" ItemsSource="{Binding}" VerticalAlignment="Center" IsSynchronizedWithCurrentItem="{x:Null}" ToolTip="Select the user." IsReadOnly="True" />

Regards,