#define D3DFVF_Vertex (D3DFVF_XYZ|D3DFVF_DIFFUSE|D3DFVF_TEX1)

LPDIRECT3DVERTEXBUFFER9 vbTerrain = NULL;
LPDIRECT3DINDEXBUFFER9 ibTerrain = NULL;

int nHeightArray[128][128];//these are the heights of each pixel on the heightmap

WORD sIndices[(6 * 127 * 127)];//these are the order in which to draw the vertices


struct Vertex
{
	float x, y, z;
	D3DCOLOR diffuse;
	float u, v;
};
Vertex TerrainData[128 * 128];//these are the actual vertices


//skipping past windows and d3d intialization code


bool InitTerrain()
{
	int nCount = 0;
	ZeroMemory(TerrainData, sizeof(TerrainData));
	for(int i = 0; i < 128; i++)
	{
		for(int j = 0; j < 128; j++)
		{
			nHeightArray[i][j] = 0;
			Vertex vTemp = {(float)(-64 + i), 0, (float)(-64 + j), D3DCOLOR_XRGB(0, 255, 0), 0.0f, 0.0f};
			TerrainData[nCount++] = vTemp;
		}
	}
	nCount = 0;
	ZeroMemory(sIndices, sizeof(sIndices));
	for(int i = 0; i != 16256; i += 128)
	{
		for(int j = 0; j < 128; j++)
		{
			sIndices[nCount++] = i + j;
			sIndices[nCount++] = i + j + 1;
			sIndices[nCount++] = i + j + 128;
			sIndices[nCount++] = i + j + 1;
			sIndices[nCount++] = i + j + 128 + 1;
			sIndices[nCount++] = i + j + 128;
		}
	}


	
	//Create Vertex Buffer

	if(FAILED(device->CreateVertexBuffer(16384 * sizeof(Vertex), 0, D3DFVF_Vertex, D3DPOOL_DEFAULT, &vbTerrain, NULL)))
		return false;
	Vertex *Vertices;
	if(FAILED(vbTerrain->Lock(0, sizeof(TerrainData), (void**)&Vertices, 0)))
		return false;
	memcpy(Vertices, TerrainData, sizeof(TerrainData));
	vbTerrain->Unlock();

	//Create Index Buffer

	int nIndexListSize = sizeof(WORD) * nCount;
	if(FAILED(device->CreateIndexBuffer(nCount, 0, D3DFMT_INDEX16, D3DPOOL_DEFAULT, &ibTerrain, NULL)))
		return false;
	VOID* indices;
	if(FAILED(ibTerrain->Lock(0, 0, (VOID**)&indices, 0)))
		return false;
	memcpy(indices, sIndices, sizeof(sIndices));//throws error here.

	ibTerrain->Unlock();

	device->SetIndices(ibTerrain);

	return true;
}

memcpy(indices, sIndices, sizeof(sIndices)); 

quote:
Syntax

HRESULT CreateIndexBuffer( UINT Length,
DWORD Usage,
D3DFORMAT Format,
D3DPOOL Pool,
IDirect3DIndexBuffer9** ppIndexBuffer,
HANDLE* pHandle
);
Parameters

Length
[in] Size of the index buffer, in bytes.
Usage