Hi,
Try splitting up the long logical expressions, like:
Code:
A:
IF DATAIN[2]=$2D THEN
  IF DATAIN[3]=$A1 THEN
    IF DATAIN[4]=$00 THEN
      IF DATAIN[5]=$CD THEN
        IF DATAIN[6]=$C2 THEN 
          X[0]=1
        ENDIF
      ENDIF
    ENDIF
  ENDIF
ELSE
 X[0]=0
ENDIF
RETURN
/Henrik.