Why is GLU_BGRA not found?

I'm building my GL application on VS2010 and the "gl.h", "glu.h" is in the Windows 7 SDK. I create mipmap with:

gluBuild2DMipmaps(GL_TEXTURE_2D,GLU_RGBA,Bitmap.bmWidth,Bitmap.bmHeight,
  GLU_RGBA,GL_UNSIGNED_BYTE,Dib_Handle);

But VS says "GLU_RGBA" and "GLU_BGRA" not found.

OpenGL ref states that these constants are开发者_如何学Go "only available if the GL version is 1.2 or greater and if the GLU version is 1.3 or greater"

Any idea how to check out why?

It's just called GL_BGRA rather than GLU_BGRA. You can use glGetString(GL_VERSION) to check the OpenGL version.