Look at the CVI example project ...\CVI\samples\userint\splash.prj.
Basically, a splash screen is a panel (with a picture control) which you display and discard before you display your main panel and RunUserInterface().
The order will be similar to the following.
1. Display the spash panel.
2. Do your initialization stuff, which might include a delay() if you want the splash panel up longer than your init takes. Just don't make the delay too long or users will get impatient.
3. HidePanel() or DiscardPanel() on your splash panel. If you may want to display it again, e.g. under Help About, hide it, don't discard it.
4. Display your main panel.
5. RunUserInterface()
You can edit the panel attributes so it doesn't have a menu bar, title bar, or frame, that it aut
o-centers, and can't be moved or resized, etc. If you hide the frame, you won't be able to double-click on the panel to edit it: you'll need to left-click once on the picture control, the goto the Edit menu (on the UIR editor menu bar) and select Panel.