Show a frame via Blizzard's "UI Panels" system.
- Table (Frame) - The UIPanel-capable frame that you want to show.
- Flag - If true, the call will allow non-"full"/non-"center" area frames to replace existing "full"/"center" frames (by forcibly closing those "blocking" frames); otherwise those would prevent all "ShowUIPanel" calls for "lesser" frames" until such high-priority frames are manually closed. This flag isn't necessary if you want to replace a "full" area frame with another "full" frame, or likewise with "center" frames. It's only necessary if you want to forcibly replace such high-priority frames with things like "left"/"doublewide"-area frames instead (which have lower priorities).
Open a GUI panel using the "UI Panels" system.