How do I do show popup?

#1
How do I do?

Does anyone know how to show a popup to tell setup that has triggered the condition of it?

I managed to make a sound, more does not help much, because gotta go into an active one to know what it was.

Here the parameter of the sound.

AlertIf (Buy, "SOUND C: \ \ Windows \ \ Media \ \ Notify.wav", "Audio alert", 2);
AlertIf (Sell, "SOUND C: \ \ Windows \ \ Media \ \ Tada.wav", "Audio alert", 2);