Not sure to understand the whole thing... but if you just want to Toggle the state of a pin with a single button... i would suggest
Code:
IF PORTB.0 = 0
    TOGGLE PORTB.1 ' or PORTB.1=PORTB.1 ^1
    WHILE PORTB.0=0 : WEND ' wait 'till button is released
    PAUSE 50 ' debounce delay
    ENDIF
Still doable in a ISR...