I am currently learning DX and I thought I might do a small 2d game, here is my half finished class that should handle the graphics that I need. The think is that every time I run the program I get a Debug error that states "variable p_GO (thats the class) is being used without being defined." I can anyone see what I did wrong, because I can''t.

class GraphicObject
{
public:
	typedef struct {
	float x, y, z, rhw; //screen coords

	float u, v;			//tex coords

	}sVertex;
		
	float CallNumVerts( );					// Calls the number of vertex points set.

	bool  InitializeDirectX( );				// Initializes the direcx graphics

	void  SetNumVerts ( int );				// Set number of vertex points needed

	void  SetUpVertex ( float x, float y );	// Set up tile position

	void  SetTileSize ( float TileSize );   // Set the size of tiles in pixels

	void  CpyToVertex ( );					// Copy the data to the vertexbuffer

	void  DestroyGraphicObject( );   // Destroys the object

private:
	sVertex *m_pVerts;	// Vertex structure

	float	m_fSize;	// Size of the tiles in pixels

	int		m_iNrTiles;	// Numbers of tiles which has been defined

	int		m_iNrVerts; // Numbers of verts needed

	
	//DX8 PARAMS

	D3DPRESENT_PARAMETERS	m_d3dpp;
	D3DDISPLAYMODE			m_d3ddm;
};

bool  GraphicObject::InitializeDirectX()
{
	if( ( ( g_pD3D = Direct3DCreate8( D3D_SDK_VERSION ) ) == NULL ) )
		return false;
	
	if( FAILED( g_pD3D->GetAdapterDisplayMode( D3DADAPTER_DEFAULT, &m_d3ddm ) ) )
		return false;
	
	ZeroMemory( &m_d3dpp, sizeof(m_d3dpp) );
	m_d3dpp.Windowed						= true;
	m_d3dpp.SwapEffect						= D3DSWAPEFFECT_FLIP;
	m_d3dpp.FullScreen_RefreshRateInHz		= D3DPRESENT_RATE_DEFAULT;
	m_d3dpp.FullScreen_PresentationInterval	= D3DPRESENT_INTERVAL_DEFAULT;
	m_d3dpp.BackBufferFormat				= m_d3ddm.Format;

	if(	FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, g_hWnd, 
				D3DCREATE_SOFTWARE_VERTEXPROCESSING, &m_d3dpp, &g_pD3DDevice ) ) )
				return false;
	if( FAILED( g_pD3DDevice->CreateVertexBuffer( sizeof(sVertex) * ( m_iNrTiles * 4 ), 0, VertexFVF,
		D3DPOOL_MANAGED, &g_pVB ) ) )
				return false;
	g_pD3DDevice->CreateVertexBuffer(sizeof(sVertex) * ( m_iNrTiles * 4 ), 0,      
                          VERTEXFVF, D3DPOOL_DEFAULT, &g_pVB);
	
	D3DXCreateTextureFromFile(g_pD3DDevice, "Texture.bmp", &g_pTexture);

	return true;
}

float GraphicObject::CallNumVerts()
{
	return m_iNrVerts;
}

void GraphicObject::SetNumVerts( int NumberOfVertexPoints )
{
	m_iNrVerts = NumberOfVertexPoints;

	m_pVerts = new sVertex [ NumberOfVertexPoints ];
}

void GraphicObject::SetUpVertex( float x, float y )
{
	
	m_pVerts[m_iNrVerts+0].x   = x;			m_pVerts[m_iNrVerts+1].x   = x+m_fSize;
	m_pVerts[m_iNrVerts+0].y   = y;			m_pVerts[m_iNrVerts+1].y   = y;
	m_pVerts[m_iNrVerts+0].z   = 1.0f;		m_pVerts[m_iNrVerts+1].z   = 1.0f;
	m_pVerts[m_iNrVerts+0].rhw = 1.0f;		m_pVerts[m_iNrVerts+1].rhw = 1.0f;
	m_pVerts[m_iNrVerts+0].u   = 0.0f;		m_pVerts[m_iNrVerts+1].u   = 1.0f;
	m_pVerts[m_iNrVerts+0].v   = 0.0f;		m_pVerts[m_iNrVerts+1].v   = 0.0f;

	m_pVerts[m_iNrVerts+2].x   = x;			m_pVerts[m_iNrVerts+3].x   = x+m_fSize;
	m_pVerts[m_iNrVerts+2].y   = y+m_fSize; m_pVerts[m_iNrVerts+3].y   = y+m_fSize;
	m_pVerts[m_iNrVerts+2].z   = 1.0f;		m_pVerts[m_iNrVerts+3].z   = 1.0f;
	m_pVerts[m_iNrVerts+2].rhw = 1.0f;		m_pVerts[m_iNrVerts+3].rhw = 1.0f;
	m_pVerts[m_iNrVerts+2].u   = 0.0f;		m_pVerts[m_iNrVerts+3].u   = 1.0f;
	m_pVerts[m_iNrVerts+2].v   = 1.0f;		m_pVerts[m_iNrVerts+3].v   = 1.0f;
		

	m_iNrVerts += 4;
}

void GraphicObject::SetTileSize( float TileSize )
{
	m_fSize = TileSize;
}

void GraphicObject::CpyToVertex()
{
	BYTE* *Ptr;
	g_pVB->Lock(0,0, (BYTE**)&Ptr, 0);
		memcpy(Ptr, m_pVerts, sizeof(m_pVerts));
	g_pVB->Unlock();
}

void GraphicObject::DestroyGraphicObject( int DestroyCode )
{
	delete [] m_pVerts;
}

// Called here!  if I remove this all is well.


bool DoInit()
{
	
	
	GraphicObject			*p_GO;
	
	p_GO->SetNumVerts( 4 );
	p_GO->InitializeDirectX();
	p_GO->SetUpVertex( 10.0f, 10.0f );
	p_GO->CpyToVertex();	
	p_GO->DestroyGraphicObject( DEST_ALL );
	
	return true;
}

Are you sure you feel comfortable enough with C++ before you start working with DX and writing a game? Because dynamic memory allocation is fundamental.