DT CMP Interrupt Problem

[Pic2008]

I'm using PIC16F877, and have 2 analog inputs IN1 and IN2. I want to generate interrupt if voltage IN1 > IN2. Do I keep reading the AD register and compare it with IN2 voltage during each CMP interrupt? Or is there a more efficient way to implement this?

define OSC 20
INCLUDE "DT_INTS-14.bas"     ' Base Interrupt System
INCLUDE "ReEnterPBP.bas"     ' Include if using PBP interrupts

ASM
INT_LIST  macro    ; IntSource,  Label,  Type, ResetFlag?
       INT_Handler    CMP_INT,  _Int_Cmp,   PBP,  yes        
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM

@    INT_DISABLE   CMP_INT     ;Comparator int

ADCON1= %00000000      'enable all analog inputs
LED var PORTB.7

loop:
'start ad here

'end ad 
pause 50
goto loop

'---[CMP - interrupt handler]----------------------------------------------
Int_Cmp:
toggle LED 

'read and store ad result here

@ INT_RETURN

I haven't finish the code above, but am getting a compilation error in Microcode "symbol not previously defined [CMIF]". PLease help.