Texture Wrapping

Hi i''ve created a 64x64 vertex grid for my terrain using DrawIndexedPrimitive() and I apply a texture to it(grass) but the texture is streched to fit on the whole terrain which all but kills the detail level, anyway how can i Wrap the texture so it is tiled over in like a 10x10 grid. I know the SetTextureStageState(0,D3DTSS_ADDRESS,D3DTADDRESS_WRAP); but i have no idea how to set the ''texture coordinates.'' ??????