add: if ( verifie_element_formulaire_existe ( TRANSACTION_FORM_DEVISE ))
context: void degrise_formulaire_operations ( void ){    if ( verifie_element_formulaire_existe ( TRANSACTION_FORM_TYPE ))	gtk_widget_set_sensitive ( GTK_WIDGET ( widget_formulaire_par_element (TRANSACTION_FORM_TYPE) ),				   TRUE );	gtk_widget_set_sensitive ( GTK_WIDGET ( widget_formulaire_par_element (TRANSACTION_FORM_DEVISE) ),				   TRUE );    if ( verifie_element_formulaire_existe ( TRANSACTION_FORM_EXERCICE ))	gtk_widget_set_sensitive ( GTK_WIDGET ( widget_formulaire_par_element (TRANSACTION_FORM_EXERCICE) ),				   TRUE );    gtk_widget_set_sensitive ( GTK_WIDGET ( vbox_boutons_formulaire ),			       TRUE );}