Function
display-dialog function displays a CAPI interface as a dialog box. display-dialog interface &key screen focus (modal t)
popup-confirmer which gives you the standard OK and Cancel button functionality.
(capi:display-dialog (capi:make-container
(make-instance
'capi:push-button-panel
:items '("OK" "Cancel")
:callback-type :data
:callbacks '(capi:exit-dialog
capi:abort-dialog))
:title "Empty Dialog"))