Add a button to the about dialog

[Daniel Leidert <daniel leidert spam gmx net>]

Hi,

I would like to add some information to the About dialog of an
application. The About-dialog is created using gtk_show_about_dialog().

Now what I did is adding the following lines after calling
gtk_show_about_dialog():

[..]
dialog = g_object_get_data (G_OBJECT (GTK_WINDOW (main_window)), "gtk-about-dialog");
but = gtk_dialog_add_button(GTK_DIALOG(dialog), _("_Features"), 99);
g_signal_connect(GTK_OBJECT(but), "clicked", G_CALLBACK(about_configure_lcb), dialog);
[..]

But this creates a button every time the About dialog is called. Now I
understand, why I get this result. But I don't know, how to workaround
it. Can you give me some help?

(the button is intended to show, which configure options were used and
which features were enabled)

Regards, Daniel