Windows in WPF

[TBBW]

Hi All,

in the 'old days' I used;

            this.Hide();

            COD01Window COD01 = new COD01Window();
            COD01.ShowDialog();

            this.Show();

The calling Window (Main Window) "waited" until the COD01 was closed.
In WPF it does not do the same it displays the COD01 window over the Main window, and yes the main window
is still visible. The hide and show gives a kind of flash.
Where do I go wrong?

Regards,

Ger