texture disappears!

I load a HDR image as a texture and I wrote shaders to map the 2 texture to a sphere but texture disappears when I click on it or when I resize the window! Here is my code for display function:

Code:

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void Draw()
{
  qobj = gluNewQuadric();
  gluQuadricTexture(qobj, GL_TRUE);

  model->GetFaces();

  glEnable(GL_CULL_FACE);

  glFrontFace(GL_CW /* or GL_CCW */ );  //default is GL_CCW
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);



  glLoadIdentity();

  glPushMatrix();
  glTranslatef(tx, ty, 0);
  glRotatef(rotx, 1, 0, 0);
  glRotatef(roty, 0, 1, 0);

  LShader.bind();
  glEnable(GL_TEXTURE_2D);
  glActiveTexture(GL_TEXTURE0);
  glBindTexture(GL_TEXTURE_2D, texture);
  gluSphere(qobj, 1, 30, 30);
  int texture_location =
      glGetUniformLocation(LShader.GetID(), "color_texture");
  glUniform1i(texture_location, texture);



  gluDeleteQuadric(qobj);

  glDisable(GL_TEXTURE_2D);


  LShader.unbind();
  glPopMatrix();
  glutSwapBuffers();
};

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Thanks in advance