Nurbs Surface texturing

I’m having trouble figuring out how to specify the u,v -> s,t points when texturing to a Nurbs Surface. My picture loads up, and if i use glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); i will get the texture repeatedly wrapped around on the surface. If I use GL_CLAMP instead, i get the picture, just centered on the surface. How do I specify the outer control points of the Nurbs surface so my texture will stretch across the entire surface? Thanks.