void RadarScreen::DisplayPlanes (Traffic *Traff_i)	{

		 EifIterator PlaneIt;
		 Plane *CrntPlane;

		 Select ();

		 PlaneIt = Traff_i->AirborneIterator();
		 while (!PlaneIt.Finished())	{
			CrntPlane = Traff_i->Airborne (PlaneIt);

			if (CrntPlane->CurPos().inField())	{
				GotoFieldPosition (CrntPlane->CurPos());

				if (CrntPlane->PType() == Jet)	{
					textcolor (JET_COLOUR);

				} else {
					assert (CrntPlane->PType() == Prop);
					textcolor (PROP_COLOUR);
				}

			} else {
				GotoFieldPosition (CrntPlane->CurPos().NextMove
					(CrntPlane->CurHead() + D180));
				textcolor (LAST_POS_COLOUR);
			}
			cprintf ("%c%d", CrntPlane->Id(), CrntPlane->CurAlt());

			PlaneIt.Forth();

		 }

	}
	void RadarScreen::UnDisplayPlanes  (Traffic *Traff_i)	{

		 EifIterator PlaneIt;
		 Plane *CrntPlane;

		 Select();

		 PlaneIt = Traff_i->AirborneIterator();
		 while (!PlaneIt.Finished())	{
			CrntPlane = Traff_i->Airborne (PlaneIt);

			PrintBackPosition (CrntPlane->CurPos());
			PlaneIt.Forth();

		 }



	}