CVI's notion of windows (panels) is different from the MDI notion of windows (multiple documents embedded in a client area). In essence, CVI speaks a different language when it comes to child windows. In CVI a child window is just a panel (not an MDI window) embedded within another panel (no client/container support the way MDI applications define it). For this and other reasons, sending messages to child windows, such as WM_MDITILE, can have unexpected.
CVI does provide functions for resizing/repositioning panels within other panels. So you could implement the tiling effect yourself (granted, this is a bit cumbersome) by repositioning all the child windows within the parent panel.
In addition, if you want the CVI child panels to contain the frame of a top-leve
l window (with the minimize, maximize and close buttons on the upper-right corner), check out the following CVI example:
http://zone.ni.com/devzone/explprog.nsf/6c163603265406328625682a006ed37d/341192d4aeb035e486256ac40078a4e8?OpenDocument
Best Regards,
Azucena
NI