As Steve repeated,

May be, a code like the one below could do the job for you, may be.

Code:
TRISA =  %00000000     'All output.
TRISB =  %01000000     'RB6 is input, rest is output.

IN_PIN VAR PORTB.6

                                                 
Loop:

    WHILE IN_PIN
        PORTA = 255
        PAUSE 200
        PORTA = 0
        PAUSE 200
    WEND
    PORTA = 0

    GOTO Loop

END
Not a real drop-in interrupt compatible code but may work in some cases.

Try...