INS and diabetes mellitus: Average patient’s knowledge about: treatment of diabetes; self - administer insulin; side effects of treatment; importance of dietary control; importance of daily exercise; danger of strenuous exercises; and precautions to avoid side effects of strenuous exercises; before and after implementation of health education among diabetic patients attending at Diabetic Health Centers in Khartoum State, Sudan; 2007 - 2010 (n=152)