Undetected Detour Function?

DWORD DetourCreate(DWORD SrcVA, DWORD DstVA, DWORD Size)
{
	DWORD DetourVA, dwProtect, i;

#define SIZEOF_JMP_REL  5

	if (SrcVA && DstVA && Size >= SIZEOF_JMP_REL)
	{
		DetourVA = (DWORD) VirtualAlloc( 
			NULL, Size + SIZEOF_JMP_REL, 
			MEM_COMMIT, PAGE_EXECUTE_READWRITE);

		if (DetourVA && VirtualProtect((VOID*)SrcVA, Size, PAGE_EXECUTE_READWRITE, &dwProtect))
		{
			for (i=0; i < Size; i++) {
				*(BYTE*)(DetourVA + i) = *(BYTE*)(SrcVA + i);
			}
			
			*(BYTE*)(DetourVA + Size + 0) = 0xE9;
			*(DWORD*)(DetourVA + Size + 1) = (SrcVA - DetourVA - SIZEOF_JMP_REL);

	    	        *(BYTE*)(SrcVA + 0) = 0xE9;
			*(DWORD*)(SrcVA + 1) = (DstVA - SrcVA - SIZEOF_JMP_REL);

			VirtualProtect((VOID*)SrcVA, Size, dwProtect, &dwProtect);

			VirtualProtect((VOID*)DetourVA, Size + 
				SIZEOF_JMP_REL, PAGE_EXECUTE_READ, &dwProtect);

	    	return DetourVA;
		}
	}

	return (0);
}