   openGL picking
  I am using the NeHe tutorial with some modifactions, with it i got picking too work, but then i need to be able to place objects after i picked them up, so for that i needed to use glOrtho(0,640,480,0,-1,1); so that i could use the mouse coords to place the object. So now i have decided that i may as well just draw everything with glOrtho(0,640,480,0,-1,1); but now picking does not work correctly, no matter where i click on the screen it detects a collision with my object, here is my selection code:void Selection(void){GLuintbuffer[512];GLinthits;GLintviewport[4];glGetIntegerv(GL_VIEWPORT, viewport);glSelectBuffer(512, buffer);(void) glRenderMode(GL_SELECT);glInitNames();glPushName(0);glMatrixMode(GL_PROJECTION);glPushMatrix();glLoadIdentity();gluPickMatrix((GLdouble) mouse_x, (GLdouble) (viewport[3]-mouse_y), 1.0f, 1.0f, viewport);gluPerspective(45.0f, (GLfloat) (viewport[2]-viewport[0])/(GLfloat) (viewport[3]-viewport[1]), 0.1f, 100.0f);glMatrixMode(GL_MODELVIEW);DrawTargets();glMatrixMode(GL_PROJECTION);glPopMatrix();glMatrixMode(GL_MODELVIEW);hits=glRenderMode(GL_RENDER);if (hits > 0){intchoose = buffer[3];x+=0.02f;pickedObject = choose;if (!object[choose].hit){object[choose].x += 0.5;}}}I am still new to openGL so i am not sure how i need to modify my code to work, if anyone can help my out that would be great. Thanks   