I am trying to start using framebuffers in my app. I fallowed Apple tutorial Using a Framebuffer Object as a Texture. And my code looks like this:

Somewhere in header file:

Code :
    GLuint framebuffer, texture;
    GLenum status;

And .m file:

Code :
   -(void)initFBO {
    glGenFramebuffersEXT(1, &framebuffer);
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer);
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0,
                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
                    GL_TEXTURE_2D, texture, 0);
    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
            NSLog(@"failed");
            } else {
            NSLog(@"success");
           }
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
    }
 
    -(void)someDrawingFunc {
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
    glClear(GL_COLOR_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, someTexture1);
    glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 0.0f);
    glVertex2f(0.0, height);
    glTexCoord2f(0.0f, 1.0f);;
    glVertex2f(0.0, 0.0);
    glTexCoord2f(1.0f, 1.0f);
    glVertex2f(width, 0.0);
    glTexCoord2f(1.0f, 0.0f);
    glVertex2f(width, height);
    glEnd();
 
    glBindTexture(GL_TEXTURE_2D, someTexture2);
    glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 0.0f);
    glVertex2f(0.0, height);
    glTexCoord2f(0.0f, 1.0f);;
    glVertex2f(0.0, 0.0);
    glTexCoord2f(1.0f, 1.0f);
    glVertex2f(width, 0.0);
    glTexCoord2f(1.0f, 0.0f);
    glVertex2f(width, height);
    glEnd();
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);
    glBindTexture(GL_TEXTURE_2D, texture);
    CGFloat verfb[] = {0, 0,
        width, 0,
        width, height,
        0, height};
    CGFloat texfb[] = {0, 0,
        1, 0,
        1, 1,
        0, 1,};
    glVertexPointer(2, GL_FLOAT, 0, verfb);
    glTexCoordPointer(2, GL_FLOAT, 0, texfb);
    glDrawArrays(GL_QUADS, 0, 4);
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    glFlush();
    }

In console I see "success", but in my app window I see:
Click image for larger version. 

Name:	PUMtV.jpg 
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Size:	3.4 KB 
ID:	842

While with same code just without using framebuffer at all, I see:
Click image for larger version. 

Name:	Screen Shot 2012-08-10 at 10.07.03 AM.jpg 
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Size:	17.6 KB 
ID:	843

What am I doing wrong?