Loop:
TRISB.0=1
TRISB.7=1
Pause 1000
HIGH RelayPinA
HIGH RelayPinB
Pause 1000
Goto Loop

The only down side to this is if you use the Port B weak pull up option. There will be a small current going through the relay constantly. Mel, would ORing the two pins at once protect from one shorting the other out for an instant, or are the diodes absolutely necessary?