OpenGL perspective overlay on ortho - opengl

Question

I have set the background texture with Ortho bounds.I have some drawings in perspective which are required to be overlaid on top of this.
Why the foreground Object in perspective cannot be seen?
void handleResize(int w, int h)
{
width=w;
height=h;
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (float)w / (float)h, 1.0, 200.0);
}
void Draw2D()
{
//ORTHO
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0f, 1024.0, 0.0, 512.0, 0.0, 1.f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, _textureId);
//Bottom
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glBegin (GL_QUADS);
glTexCoord2d(0.0,0.0); glVertex2d(0.0,0.0);
glTexCoord2d(1.0,0.0); glVertex2d(1024.0,0.0);
glTexCoord2d(1.0,1.0); glVertex2d(1024.0,512.0);
glTexCoord2d(0.0,1.0); glVertex2d(0.0,512.0);
glEnd();
}
void Draw3D()
{
//PERSPECTIVE
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (float)width / (float)height, 1.0, 200.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -6.0f);
glutWireCube(0.5);
}
void drawScene()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Draw3D();
Draw2D();
glutSwapBuffers();
}
#Matso..I am using below function for the depth testing
void initRendering()
{
//glEnable(GL_DEPTH_TEST);//Comment this
glDepthMask(false);//Use this
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
Image* image = loadBMP("earth.bmp");
_textureId = loadTexture(image);
delete image;
}
Introducing
glDepthMask(false);
did the trick.I am able to view my perspective drawings.