GLPaint Problem with OPENGL and Core Graphics Frameworks

Question

I am a newbie trying to use OpenGl. I began by trying to write something similar to GLPaint. However, the moment I import the OpenGL framework, I get errors referring to missing information from Core Graphics but I cannot import Core Graphics since it is not in the list of existing frameworks. I understand it is in ApplicationServices, but importing that did not help. I am importing using the "relative to existing SDK" reference when adding an existing framework. Errors include:
Line Location CGBitmapContext.h:27: error: expected declaration specifiers or '...' before 'CGBitmapInfo'

Line Location CGBitmapContext.h:28: error: expected '=', ',', ';', 'asm' or 'attribute' before 'CG_AVAILABLE_STARTING'

and many more. What am I missing???