protected SystemWindow (IntPtr handle, EmbeddingOptions options) {
			Handle = handle;
			_handleRef = new HandleRef(this, Handle);
			_originalStyle = WinAPI.GetWindowLongPtr(Handle, WinAPI.GWL.STYLE);
			_originalExStyle = WinAPI.GetWindowLongPtr(Handle, WinAPI.GWL.EXSTYLE);
			WinAPI.RECT rect;
			WinAPI.GetWindowRect(_handleRef, out rect);
			_originalPosition = new WinAPI.Position(rect);
			_embeddingOptions = options;
		}
		void SetOriginalStyle () {
			WinAPI.RECT rect;
			WinAPI.GetWindowRect(_handleRef, out rect);
			WinAPI.Position pos = new WinAPI.Position(rect);
			Visible = false;
			WinAPI.SetWindowLongPtr(new HandleRef(this, Handle),
				WinAPI.GWL.STYLE, new UIntPtr(_originalStyle));
			WinAPI.SetWindowLongPtr(new HandleRef(this, Handle),
				WinAPI.GWL.EXSTYLE, new UIntPtr(_originalExStyle));
			_embeddable = false;
			Visible = true;
			WinAPI.SetWindowPos(Handle, WinAPI.HWND.TOP, pos.X, pos.Y,
				pos.Width, pos.Height, WinAPI.SWP.NOZORDER);
		}