pcb layout of a simetric dc source +12 +5 -5 -12

this is a complete circuit of a simetric dc source with 4 options of voltages (12 +5 -5 -12). of course with the respective pcb layout. the maximun current that the circuit can provide is 0.5 A without disipation element(and 1 A with a decent disipation element) the project was made with IC 7805,7812,7905,7912. just available for venezuela