please help

Please I''m trying to understand what''s going wrong with this piece of code : //includes...dinput.h and others extern HINSTANCE hGlobalInstance ; LPDIRECTINPUT8 lpDI8 ; LPDIRECTINPUTDEVICE8 lpDIDV8 ; HRESULT hr ; void CreateDIObject(void) //declarations included in headers { hr = DirectInput8Create(hGlobalInstance,DIRECTINPUT_VERSION, &IID_IDirectInput8,NULL); //using & before GUID ''cause the code is C if (FAILED(hr)) //...do something } // the previous function works // but following one that causes problems... void CreateDIDevice(void) { hr = lpDI8->CreateDevice(&GUID_SysKeyboard,&lpDIDV8,NULL) if (FAILED(hr))//do something... } this is the error I get from compiler : Compiling... app_input.c C:\msvc++\unisoft\app_input.c(31) : error C2039: ''CreateDevice'' : is not a member of ''IDirectInput8A'' c:\dxsdk\include\dinput.h(2622) : see declaration of ''IDirectInput8A'' Error executing cl.exe. Creating browse info file... unisoft.exe - 1 error(s), 0 warning(s) I''ve set the right paths and included necessary headers and libs(i mean dinput8.lib dxguid.lib ...) Maybe it''s a simple question but it really get me stuck. If someone could give me a hint I''le be very grateful. Thanks in advance