I saw this function previously but the description does not appear to mean that updates to the screen are done in a batch fashion. Does it actually work like VFP lockscreen? The documentation says:
"If an application attempts to draw within a locked window, the system records the extent of the attempted operation in a bounding rectangle. When the window is unlocked, the system invalidates the area within this bounding rectangle, forcing an eventual WM_PAINT message to be sent to the previously locked window and its child windows. If no drawing has occurred while the window updates were locked, no area is invalidated."

Again Thanks!