diff --git a/GDP/D3D9/Direct3D.cpp b/GDP/D3D9/Direct3D.cpp
index dfaec76..479281c 100644
--- a/GDP/D3D9/Direct3D.cpp
+++ b/GDP/D3D9/Direct3D.cpp
@@ -1,5 +1,6 @@
 #include "Direct3D.h"
 #include "Utilities.h"
+#include <random>
 
 INT Direct3D::init(HWND hWnd, UINT width, UINT height, BOOL isFullscreen)
 {
@@ -50,10 +51,28 @@ INT Direct3D::init(HWND hWnd, UINT width, UINT height, BOOL isFullscreen)
 
 void Direct3D::beginScene()
 {
+	_pD3DDevice->BeginScene(); // init a frame, after this call we are allowed to do draw calls
+
+	// change background color
+	static std::default_random_engine e;
+	static std::uniform_int_distribution<int> d(0, 255);
+
+	_pD3DDevice->Clear(
+		0, nullptr, // areas to clear, null -> everything
+		D3DCLEAR_TARGET, // what to clear, bitmask
+
+		// how to clean
+		//D3DCOLOR_XRGB(d(e), d(e), d(e)), //random color
+		//D3DCOLOR_XRGB(255, 0, 0), // red color
+		D3DCOLOR_XRGB(0, 0, 0), // black color
+		1.0f, 0xFFFFFFFF
+	);
 }
 
 void Direct3D::endScene()
 {
+	_pD3DDevice->EndScene(); // close a frame, after this call we are not allowed to do draw calls
+	_pD3DDevice->Present(nullptr, nullptr, nullptr, nullptr); // swap back- with frontbuffer
 }
 
 void Direct3D::deInit()
diff --git a/GDP/D3D9/Window.cpp b/GDP/D3D9/Window.cpp
index dd38e7c..05c95d1 100644
--- a/GDP/D3D9/Window.cpp
+++ b/GDP/D3D9/Window.cpp
@@ -16,12 +16,15 @@ INT Window::init(HINSTANCE hInstance, UINT width, UINT height)
 	if (!RegisterClass(&wc)) return 100;
 
 	// 3. adjust window size (optional)
+	DWORD style;
+	style = WS_OVERLAPPEDWINDOW; // window with border & title
+	//style = WS_POPUP; // borderless window
 
 	// 4. create window instance
 	_hWnd = CreateWindow(
 		wc.lpszClassName, // class name for window instance
 		wc.lpszClassName, // window title
-		WS_OVERLAPPEDWINDOW, // visual window style
+		style, // visual window style
 		100, 100, // window position (left-top corner)
 		width, height, // window size
 		nullptr, // handle to parent window
@@ -75,7 +78,7 @@ LRESULT WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 		PostQuitMessage(0);
 		return 0;
 	case WM_KEYDOWN:
-		if (wParam == VK_ESCAPE) 
+		if (wParam == VK_ESCAPE)
 		{
 			DestroyWindow(hWnd);
 			return 0;