Rob,

Why don't you check this out.

Code:
'PIC 12F683

#CONFIG 
   __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF
#ENDCONFIG


DEFINE OSC 4 '4mhz ocsillator
ANSEL = %00000010 'pin 6 analog
CMCON0 = %00000100 'comparator mode
VRCON = %10101000 'voltage reference
TRISIO = %00000010 'pin 6 input

PAUSE 50 'wait for hardware to settle

ON INTERRUPT GOTO int1 'interrupt handler is int1
INTCON = %11001000 'enable GIE and GPIE; clear GPIF
PIE1 = %00001000 'enable comparator interrupt

POT1 VAR CMCON0.6 'read potentiometer
LED VAR GPIO.2 'led pin 5
loop1 var word 'loop1 counter

bitTest var bit 'Debug test bit.  Set/Clear in ISR and Check in main


high LED    'Start with LED ON
pause 500   'Pause .5 secs so you can see the LED turn on

bitTest = POT1  'Take initial reading of input voltage state
Loop1 = 0

ENABLE
main:

    IF bitTest = 1 THEN 'input voltage is < reference voltage  
        low LED
        nap 1
    else    'bitTest = 0 - input voltage is > reference voltage
        GOTO FLASH
    ENDIF
        
    GOTO main


ENABLE
FLASH:
    do
        for loop1 = 1 to 1000
            HIGH LED
            PAUSE 1
        NEXT LOOP1
        
        for loop1 = 1 to 1000
            LOW LED
            PAUSE 1
        NEXT LOOP1
        
        IF bitTest = 1 THEN
            GOTO main
        ENDIF
    
    LOOP
  
    
DISABLE 'disable interrupts in handler
int1:
    
if PIR1.3 = 1 then  'Comparator Interrupt fired (must be cleared before resume)
bitTest = pot1
ENDIF 

INTCON =%11001000 
PIR1 = %00000000 'reset CMIF
RESUME 'where left off
ENABLE 'enable interrupts