This may be more helpful to you. This is the same thing, but done using DT's instant interrupts. You also need to INCLUDE the DT_INTS and ReEnterPBP files relevant to your PIC.

Code:
ASM
INT_LIST macro ;    IntSource, Label,       Type, ResetFlag?
        INT_Handler TMR0_INT,  tmr0_handler, PBP,  yes
        INT_Handler INT_INT,   int_handler,  PBP,  yes
    endm
    INT_CREATE 
ENDASM

@ INT_ENABLE TMR0_INT
@ INT_ENABLE INT_INT

main:
' your main program
goto main

tmr0_handler:
oDimmer=1
@ INT_RETURN

int_handler:
TMR0=DimmerVal
oDimmer=0
@ INT_RETURN