VBO mapping problem

i’m having a problem with using glMapBufferARB(…). I can render by using glBufferDataARB(…) however. The following is how i set up VBO calls in my rendering code (i call glGenBuffer/glBindBuffer in my init function)

glBufferDataARB(GL_ARRAY_BUFFER_ARB, 80000*3*sizeof(float), NULL, GL_STREAM_DRAW_ARB);
float *mapper = (float*)glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
for (int i = 0; i < this->num_vertices * 3; i++) {
	mapper[i] = this->m_pVertices[i];

It seems that glMapBuffer(…) call causes an access violation error.


never mind, i forgot to initialize opengl extensions … stupid … lol