hooking messageboxw

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

#define MH_DEFTRAMPOLINE(pFuncName) \
    BYTE *orig_##pFuncName; BYTE *tramp_##pFuncName
#define MH_ALLOCTRAMPOLINE(pTrampolinePtr, bSize) \
    pTrampolinePtr = (BYTE*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, bSize+5)
#define MH_FREETRAMOLINE(pTrampolinePtr) \
    HeapFree(GetProcessHeap(), 0, pTrampolinePtr)

/*returns pointer to trampoline function*/
BYTE *MH_TrampolineAdd(BYTE *pOrigFunc, BYTE *pNewFunc, BYTE *pTrampolineFunc, BYTE bSize)
{
    BYTE bTemp;
    DWORD dwOldProt;
    VirtualProtect((void*)pTrampolineFunc, bSize+5, PAGE_EXECUTE_READWRITE, &dwOldProt);
    VirtualProtect((void*)pOrigFunc, bSize, PAGE_EXECUTE_READWRITE, &dwOldProt);
    bTemp = bSize;
    while (bTemp-- > 0) pTrampolineFunc[bTemp] = pOrigFunc[bTemp];
    pTrampolineFunc += bSize;
    pTrampolineFunc[0] = 0xE9; //JMP [rel16/32]
    *(DWORD*)(pTrampolineFunc+1) = (DWORD)((pOrigFunc+bSize - pTrampolineFunc) - 5);
    pOrigFunc[0] = 0xE9; //JMP [rel16/32]
    *(DWORD*)(pOrigFunc+1) = (DWORD)((pNewFunc - pOrigFunc) - 5);
    bTemp = 5; while (bTemp++ < bSize) pOrigFunc[bTemp] = 0x90;
    VirtualProtect((void*)pOrigFunc, bSize, dwOldProt, &dwOldProt);
    return (pTrampolineFunc - bSize);
}

/*returns pointer to trampoline function*/
BYTE *MH_TrampolineRemove(BYTE *pOrigFunc, BYTE *pTrampolineFunc, BYTE bSize)
{
    DWORD dwOldProt;
    VirtualProtect((void*)pOrigFunc, bSize, PAGE_EXECUTE_READWRITE, &dwOldProt);
    while (bSize-- > 0) pOrigFunc[bSize] = pTrampolineFunc[bSize];
    VirtualProtect((void*)pOrigFunc, bSize, dwOldProt, &dwOldProt);
    return pTrampolineFunc;
}

MH_DEFTRAMPOLINE(MessageBoxW);
typedef int (WINAPI *_MessageBoxW)(HWND, LPCTSTR, LPCTSTR, UINT);
_MessageBoxW o
int WINAPI new_MessageBoxW(HWND hwnd, LPCTSTR text, LPCTSTR title, UINT utype)
{
    char *newTitle = NULL;
    newTitle = (char*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, lstrlenW(title) + 15);
    lstrcpyW(newTitle, L"=|MicroHook|= "); if (title != NULL) lstrcatW(newTitle, title);
    int ret = ((_MessageBoxW)(tramp_MessageBoxW))(hwnd, text, newTitle, utype);
    MessageBoxW(0, L"WTF HOOKED", 0, 0);
    HeapFree(GetProcessHeap(), 0, newTitle);
    return ret;
}

BOOL WINAPI DllMain(HINSTANCE hInst, DWORD dwReason, LPVOID lpvReserved)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        orig_MessageBoxW = (BYTE*)GetProcAddress(LoadLibraryA("user32.dll"), "MessageBoxW");
        MH_ALLOCTRAMPOLINE(tramp_MessageBoxW, 5);
        MH_TrampolineAdd(orig_MessageBoxW, (BYTE*)&new_MessageBoxW, tramp_MessageBoxW, 5);
    }
    else if (dwReason == DLL_PROCESS_DETACH)
    {
        MH_TrampolineRemove(orig_MessageBoxW, tramp_MessageBoxW, 5);
        MH_FREETRAMOLINE(tramp_MessageBoxW);
    }
    return (BOOL)1;
}