SDL and OpenGL resize window event question

So basically my question is im making a 2D game with openGL and SDL.

So what im trying to do is resize the game and have the openGL quad scale to the size my window becomes.

void CApp::OnResize(int w, int h){

textureWidth = (float)w;
textureHeight = (float)h;

SDLWindow::SetGLWindow(w, h, Surf_Display);

}


bool SDLWindow::SetGLWindow(int width, int height, SDL_Surface * Surf_Display)
{
if((Surf_Display = SDL_SetVideoMode(width, height, 32, SDL_HWSURFACE | SDL_OPENGL | SDL_RESIZABLE)) == NULL) {
    return false;
    }

glClearColor(0, 0, 0, 0);
glClearDepth(1.0f);

glViewport(0, 0, width, height);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();

glOrtho(0, width, height, 0, 1, -1);

glMatrixMode(GL_MODELVIEW);

glEnable(GL_TEXTURE_2D);

glLoadIdentity();

return true;

}

So this works just fine. However while resizing the window, the image isnt scaling. It only scales after i release the mouse button. I am curious if i can scale the image at the same time?